Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
School of Distance Education UNIVERSITY OF CALICUT SCHOOL OF DISTANCE EDUCATION B Sc. Mathematics (2011 Admn.) III SEMESTER COMPLEMENTARY COURSE STATISTICAL INFERENCE QUESTION BANK 1. Random sample taken from a population then the function of sample values is known as: (i)Parameter (ii) Statistic (iii) population (iv) Nome of these. 2. The probability distribution of a statistic is, (i) Sampling distribution (ii) distribution function (iii) Mass function (iv) None of these 3. A population characteristic, such as a population mean, is called (i) A statistic (ii) A parameter (iii) A sample (iv) The mean deviation 4. Which of the following is a sampling distribution: (i) Binomial (ii) Poisson (iii) Chi-square 5. A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were determined to be 80 and 12 respectively. The standard error of the mean is (i) 1.2 6. (ii) 0.8 (iii) 12 (iv) None of these (iv) 8 Since the sample size is always smaller than the size of the population, the sample mean (i) Must always be smaller than the population mean (ii) Must be larger than the population mean (iii) Must be equal to the population mean (iv) Can be smaller, larger, or equal to the population mean 7. For a population with any distribution, the form of the sampling distribution of the sample mean is, (i) Sometimes normal for large sample sizes (ii) Sometimes normal for all sample sizes (iii) Always normal for all sample sizes (iv) Always normal for large sample sizes 8. As the sample size increases, the (i) Standard deviation of the population decreases (ii) Population means increases (iii) Standard error of the mean decreases (iv) Standard error of the mean increases Statistical Inference Page 1 School of Distance Education 9. Doubling the size of the sample will (i) Reduce the standard error of the mean to one-half its current value (ii) Reduce the standard error of the mean to approximately 70% of its current value (iii) Have no effect on the standard error of the mean (iv) Double the standard error of the mean 10. In point estimation (i) Data from the population is used to estimate the population parameter (ii) Data from the sample is used to estimate the population parameter (iii) Data from the sample is used to estimate the sample statistic (iv) The mean of the population equals the mean of the sample 11. The sample statistic s is the point estimator of (i) 12. 13. 14. 15. 16. 17. (iii) x (iv) p The sample mean is the point estimator of (i) (ii) (iii) x (iv) p (ii) The probability distribution of the sample mean is called the (i) Central probability distribution (ii) sampling distribution of the mean (iii) Random variation (iv) standard error The expected value of the random variable x is, (i) The standard error (ii) the sample size (iii) The size of the population (iv) None of these A normal population has a mean of 75 and a standard deviation of 8. A random sample of 800 is selected. The expected value of x is, (i) 75 (ii) 8 (iii) 7.5 (iv) p As the sample size becomes larger, the sampling distribution of the sample mean approaches a, (i) Binomial distribution (ii) Poisson distribution (iii) Normal distribution (iv) chi-square distribution Whenever the population has a normal probability distribution, the sampling distribution of x is a normal probability distribution for, (i) Only large sample sizes (ii) only small sample sizes (iii) Any sample size (iv) only samples of size thirty or greater 18. m.g.f. of the mean of n random samples taken from N ( , ) is, t 2 2 t 2 2 t t 2 2 t t t t n 2n 2n 2 (i) e (ii) e (iii) e (iv) e 19. If Z follows standard normal distribution, P ( Z 1.67) is (i) 0.5 (ii) 0.64 (iii) 0.045 Statistical Inference (iv) 0.45 Page 2 School of Distance Education 20. The probability distribution of all possible values of the sample proportion p is the (i) Probability density function of p (ii) Sampling distribution of x (iii) Same as p , since it considers all possible values of the sample proportion (iv) Sampling distribution of p 21. If X follow standard normal distribution, then Y X 2 follows, (i) Normal (ii) Chi-square with 2 d.f. (iii) Chi-square with 1 d.f. (iv) Nome of these 22. The range of a chi-square variable is, (i) 0 to n (ii) 0 to 23. For random variable following chi-square distribution, (i) mean = 2(variance) (ii) 2(mean) = variance (iii) Mean = variance (iv) None of these 24. The mean of a chi-square random variable with ‘n’ d.f. is, (i) 2n (ii) n+2 (iii) n (iv) None of these 25. Variance of a chi-square random variable with ‘n’ d.f. is, (i) 2n (ii) n+2 (iii) n (iv) None of these 26. M.g.f. of a random variable following chi-square distribution with ‘n’ d.f. is, n (i) (1 2t ) 2 27. (ii) (1 2t ) n 2 (iii) to n (iii) (1 t ) 2 (iv) None of these (iv) (1 t ) n 2 1 2 M.g.f. of the square of a standard normal random variable is, 1 (i) (1 2t ) 2 (ii) (1 2t ) 1 2 1 (iii) (1 t ) 2 (iv) (1 t ) 28. If X and Y are two independent ch-square variables with degrees of freedom 3 and 4 respectively, then Z=X+Y follows, (i) Chi-square with 7 d.f. (ii) Chi-square with 12 d.f. (iii) Chi-square with 1 d.f. (iv) None of these 29. Chi–square table gives the values of 2( ) for a 2 variable with various degrees of freedom and for various values of , such that, (i) P ( 2 2 ( ) ) (ii) P ( 2 2 ( ) ) . (iii) P ( | 2 | 2( ) ) 30. (iv) None of these x If X 1 , X 2 ,..., X n are n random samples taken from N ( , ) , then Y i follows, i 1 (i) 2 (n 1) (ii) 2 (1) (iii) 2 (n 1) (iv) 2 (n) Statistical Inference n 2 Page 3 School of Distance Education 31. The probability distribution of the sum of squares of ‘n’ independent standard normal random variables is, (i) Normal 32. 33. (ii) Chi-square (iii) t (iv) None of these x If X is a uniform random variable over [0, ] , then Y 2 log e ( ) follow (i) Normal (ii) Chi-square with ‘n’ d.f. (iii) Exponential (iv) None of these If X ~ 2 (n) , then mode of X is at, (i) n (ii) n-1 (iii) n-2 (iv) None of these 34. As n become large a chi-square variable with n degrees of freedom follows, (i) N (n, 2n ) (ii) N (n, 2n ) (iii) N (2n, 2n ) (iv) None of these 35. Given P ( 2 (15) k ) 0.80 . Then the value of k is, (i) - 10.307 36. (ii) + 10.307 (iii) 6.307 (iv) None of these For two independent random variables X and Y, where X ~ N (0,1) and Y ~ 2 (n) , then Z follows t-distribution with n degrees of freedom, if Z is, (i) Y X (ii) X Y (iii) X n (iv) None of these n Y n 37. ‘student’ is the penname of, (i) Newton (ii) Chebychev (iii) Laplace (iv) Gosset 38. The range of a t variable is, (i) 0 to n (ii) 0 to (iii) to (iv) None of these 39. The p.d.f. of a t-variable with n d.f. is, n 1 n 1 2 2 t (i) 2 1 n 1 2 n 1 n 1 2 2 t 2 (iii) 1 n n n 2 (ii) n 1 n 1 2 2 t 2 1 n n n 2 (iv) None of these 40. For a random variable t following t distribution with 7 d.f., the mode is, (i) 0 (ii) 7 (iii) 6 (iv) None of these 41. A statistic following t distribution with n-1 d.f. is, (i) ( X ) n 1 S Statistical Inference (ii) ( X ) n 1 (iii) ( X ) n S (iv) None of these Page 4 School of Distance Education 42. If X1 and X 2 are two independent standard normal variables, then t 2X 1 X 12 X 22 follows, (i) Chi-square distribution (iii) F- distribution 43. Tables of t-distribution gives the values of t for various degrees of freedom and for various value of , such that, (i) P(| t | t ) 44. (ii) t – distribution (iv) None of these The statistics (ii) P(t t ) X1 X 2 n1S 1 n2 S 22 1 1 n1 n2 2 n1 n1 2 (iii) P(| t | t ) (iv) None of these follows, (i) t- Distribution with n1 n2 1 d.f. (ii) t- Distribution with n1 n2 2 d.f. (iii) F- distribution with ( n1 , n2 ) d.f. (iv) None of these 45. 46. If t follow t-distribution with ‘n’ degrees of freedom, then Z t 2 follows, (i) F- distribution with (1,n) d.f. (ii) F- distribution with (n,1) d.f. (iii) Chi- distribution (iv) None of these The ratio of the squares of two independent standard normal random variables is (i) An F- random variable with (1, 1) degree of freedom. (ii) An F- random variable with (n, 1) degree of freedom. (iii) An F- random variable with (1,n) degree of freedom. (iv) None of these 47. 48. 49. If F follow F distribution with (m, n) degrees of freedom then, 1/F follows , (i) t- Distribution with m d.f. (ii) t- distribution with n d.f. (iii) F- distribution with (n, m) d.f. (iv) None of these If t ~ t( n ) , then as n , t follows, (i) F- distribution with (1,n) d.f. (ii) F- distribution with (n,1) d.f. (iii) N(0,1) (iv) None of these If t ~ t(5) , the value of ‘a’ such that, P ( a t a ) 0.98 is (i) 3.365. 50. (ii) 2.365. (iii) 1.365. (iv) None of these Parameters are (i) Function of sample values (ii) Function of population values (iii) The averages taken from a sample (iv) Function of either a sample or a population values Statistical Inference Page 5 School of Distance Education 51. Sampling distribution of x is the (i) Probability distribution of the sample mean (ii) Probability distribution of the sample proportion (iii) Mean of the sample (iv) Mean of the population 52. If n increases, the student’s t distribution tends to (i) Normal 53. (ii) F (iv) None of these The ratio of two independent standard normal random variables is, (i) t (1) 54. (iii) Cauchy (ii) F(1,1) (iii) N(0,1) (iv) None of these (iii) Gosset (iv) None of these (iii) to (iv) None of these F distribution was invented by (i) Fisher (ii) Snedecor 55. The range of F variable is, (i) 0 to n (ii) 0 to 56. Let independent samples of sizes n1 and n2 are taken from normal population with mean and standard deviation . Let S12 and S 22 are the respective sample variance, then F n1S12 (n2 1) follows, n2 S 22 (n1 1) (i) F (n1 1, n2 1) 57. (ii) F (n1 , n2 ) 1 2 1 2 1 2 (iv) None of these Mode of F ~ F (n1 , n2 ) is , (i) F = n2 n1 2 n1 n2 2 (ii) F = (iii) F = n2 n1 2 n2 n2 2 (iv) None of these n1 n1 2 n1 n2 2 The ratio of the squares of two independent standard normal random variables is, (i) F (n1 , n2 ) 60. , (ii) P( Fn ,n F ) (iii) P Fn ,n F 59. (iv) None of these Tables of F-distribution gives the values of F for various values of n1 , n2 and such that, (i) P( Fn ,n F ) 58. (iii) F (1,1) (ii) F (1, n2 ) (iii) F (1,1) (iv) None of these If X following F distribution with n1 , n2 degrees of freedom Y follow F distribution with n2 , n1 degrees of freedom. Then, (i) P ( X c ) P ( Y c ) (ii) P ( X c ) P ( Y 1 ) c (iii) P ( X c ) P ( Y c ) (iv) P ( X c ) P ( Y 1 ) c Statistical Inference Page 6 School of Distance Education 61. If X following F distribution with n , n degrees of freedom. If , ( ) are such that P ( X ) P ( X ) . Then the value of . is, (i) 2 62. (ii) 1 (iii) 1/2 (iv) None of these If X following F distribution with n1 , n2 degrees of freedom, then as n2 , Y= n1 X follows, (i) 2 n1 63. 68. 71. 72. 2X 1 X X 22 2 1 follows, (iii) t 1 (iv) None of these (ii) Fermat (iii) Fisher (iv) None of these (ii) estimate (iii) Variance (iv) None of these (ii) a population parameter (iii) A mean estimator (iv) a point estimate An unbiased estimator of a parameter is an estimator t with , (ii) E (t ) (iii) E (t ) (iv) None of these (iii) E (t ) (iv) None of these An estimator is biased, when, (ii) E (t ) The estimator with smallest variance is; (i) Unbiased estimator (ii) consistent estimator (iii) Efficient estimator (iv) sufficient estimator Any statistic suggested as an estimator for a population parameter is a, (i) Point estimator (ii) Interval estimator (iii) Unbiased estimator (iv) None of these A property of a point estimator that occurs whenever larger sample sizes tend to provide point estimates closer to the population parameter is known as, (i) Unbiasedness 73. (ii) t n (i) A parameter (i) E (t ) 70. (iv) None of these A single numerical value used as an estimate of a population parameter is known as, (i) E (t ) 69. (iii) greater than one A sample constant representing the population parameter is known as, (i) Expectation 67. (ii) less than one The theory of estimation was founded by (i) Laplace 66. (iv) None of these If X1 and X 2 are two independent standard normal variables, then t (i) t 2 65. (iii) t n1 For a random variable following F distribution, the mode is always, (i) one 64. (ii) 2 n2 (ii) efficiency For the random sample x1 , x2 ,..., xn (iii) consistency (iv) None of these taken from B (1, p ) , show that s an unbiased n estimator p 2 , where T xi is, i 1 (i) T (T 1) n Statistical Inference (ii) T (T 1) (n 1) (iii) T (T 1) n(n 1) (iv) (T 1) n(n 1) Page 7 School of Distance Education 74. E (tn ) or , as n for, (i) Unbiasedness 75. (ii) efficiency (ii) consistent (ii) consistent (iv) None of these (iii) efficient (iv) sufficient (iii) efficient (iv) sufficient For the random sample x1 , x2 ,..., xn taken from N ( , ) , then sample variance is a -------estimator of the population variance. (i) Unbiased 78. (iii) consistency p If tn , then tn is a ----- estimator of . (i) Unbiased 77. V (tn ) 0, as n are sufficient conditions For the random sample x1 , x2 ,..., xn taken from Poisson population with parameter , nx is ------------ estimator . n 1 (i) Unbiased 76. and Let x1 , x2 ,..., xn (ii) consistent (iii) efficient (iv) sufficient be the random sample taken from a population with p.d.f. f ( x, ) x 1 ; 0 x 1, 0 . Then a sufficient estimator for is, (i) n xi (ii) 80. 82. 84. n x i 1 (iv) None of these 2 i (i) Unbiased, consistent (ii) biased, efficient (iii) Consistent, unbiased (iv) None of these Let t be the most efficient estimator for the parameter , then efficiency of any other unbiased estimator t1 of is defined as, SD(t1 ) var(t ) (ii) E (t1 ) SD(t ) var(t1 ) (iii) E (t1 ) var(t1 ) var(t ) (iv) E (t1 ) var(t ) var(t1 ) Given two unbiased point estimators of the same population parameter, the point estimator with the smaller variance is said to have, (i) Smaller relative efficiency (ii) greater relative efficiency (iii) Smaller consistency (iv) larger consistency MLE is always need not be, (i) Unbiased 83. (iii) Sample variance is not a ----- estimator, but it is a ---- estimator for population variance (i) E (t1 ) 81. xi i 1 i 1 79. n (ii) efficient (iii) consistent The MLE of for the following distribution f ( x ) (iv) None of these 1 | x | e , x is, 2 (i) Mean of samples (ii) Maximum value of the samples (iii) Minimum value of the samples (iv) Median of the samples The MLE of , based on random samples parameter is, (i) x Statistical Inference (ii) x 2 (iii) nx taken from Poisson population with (iv) None of these Page 8 School of Distance Education 85. The X: moment 1 2 estimate 3 of , 4 if the 1 1 1 1 ; 4 4 4 4 frequencies are 1,5,7 and 7 respectively is, 0 1, f ( x) : (i) 0.4 86. 87. 88. (ii) 0.5 (iii) 0.6 masses are and the observed (iv) None of these In case of finding the confidence interval for mean of a normal population with known SD, the table values are taken from, (i)t - table (ii) standard normal table (iii) Chi-square table (iv) None of these In case of finding the confidence interval for mean of a normal population with unknown SD, the table values are taken from, (i)t - table (ii) standard normal table (iii) Chi-square table (iv) None of these If an estimator Tn of population parameter converges in probability to as n tends to infinity is said to be, (i) Unbiased 89. probability The estimator (ii) efficient x n (iii) consistent (iv) None of these of population mean is, x (i) Unbiased 90. 92. 93. (iv) None of these (ii) efficiency (iii) consistency (iv) None of these Factorization theorem for sufficiency is known as, (i)Fisher-Neyman theorem (ii) Cramer-Rao theorem (iii) Rao-Blackwell theorem (iv) None of these If the expected value of an estimator ‘t’ is not equal to its parameter , then ‘t’ is (i) Unbiased estimator of (ii) biased estimator of (iii) Sufficient estimator of (iv) None of these Sample median is always a ---- estimator of the population mean (i) Biased 94. (iii) both A property of a point estimator that occurs whenever the expected value of the point estimator is equal to the population parameter it estimates is known as (i) Unbiasedness 91. (ii) consistent (ii) efficient (iii) consistent (iv) None of these If tn is a sufficient statistic for based on n random samples, then function of, (i) Only 95. (ii) tn only log L is a (iii) tn and only (iv) None of these In common the estimators obtained by the method of MLE are (i) More efficient (ii) less efficient (iii) can’t say about efficiency (iv) None of these Statistical Inference Page 9 School of Distance Education 96. 97. If sample mean is an estimator of population mean ,it is a --- estimator of population mean (i) Unbiased and efficient (ii) biased and efficient (iii) Unbiased and inefficient (iv) None The value taken by an estimator is known as, (i) Statistic 98. (ii) Estimate (iii) size (iv) none of these If a sufficient statistic exist for a parameter, then it will be a function of, (i)Moment estimator (ii) M L estimator (iii) Unbiased estimator 99. (iv) None of these. Bias of an estimator can be (i) Positive (ii) negative (iii) either (iv) None 100. For samples taken from N ( , ) , unbiased estimator of 2 is n 1 S 2 nS 2 (i) S (ii) (iii) (iv) None of these n 1 n 101. An estimator t1 for the parameter is more efficient than another estimator t2 if, 2 (i) V (t1 ) V (t2 ) (ii) V (t1 ) V (t2 ) (iii) V (t1 ) V (t2 ) (iv) Nome of these 102. An estimator tn which contains all information about the parameter contains in the sample is, (i) an unbiased estimator (ii) a consistent estimator (iii) a sufficient estimator (iv) None of these 103. If x1 , x2 ,....xn be a random sample from a Bernoulli population p x (1 p)1 x . Then a sufficient estimator for p is, (i) xi (ii) xi (iii) maximum of x1 , x2 ,....xn (iv) None of these 104. Sample standard deviation is a ------- estimator of population standard deviation. (i) Unbiased (ii) biased (iii) sufficient (iv) efficient 105. If t is a consistent estimator of , then, (i) t is also a consistent estimator of 2 (ii) t 2 is also a consistent estimator of (iii) t 2 is also a consistent estimator of 2 (iv) None of these 106. The inequality helps us to obtain an estimator with minimum variance is, (i) Tchebycheve’s inequality (ii) Cramer- Rao inequality (iii) Jenson’s inequality (iv) None of these 107. The method of M.L.E. is established by, (i) Fisher (ii) Newton (iii) Bernoullie (iv) None of these 108. The set of equations obtained in the process of least square estimation are called (i) Normal equations (ii) Intrinsic equations (iii) Simultaneous equations (iv) All the above Statistical Inference Page 10 School of Distance Education 109. The estimator obtained by the method of moments are ---- in comparison with the estimator obtained by the method of MLE (i) Less efficient 110. (ii) More efficient (iii) equally efficient (iv) None of these MLE of , by the random samples x1 , x2 ,....xn taken from the population with p.d.f. 1 f ( x, ) , 0 x is, 1 (i) x (ii) max of x1 , x2 ,....xn (iii) min of x1 , x2 ,....xn (iv) x 111. The probability that an interval contains the parameter value is called, (i)Confidence limit (iii) Confidence interval 112. (ii) Confidence coefficient (iv) None of these For finding the confidence interval for using samples x1 , x2 ,....xn taken from N ( , ) , when is unknown, we use the statistic following (i) Normal distribution (ii) F- distribution (iii) Chi- distribution (iv) t- distribution 113. MLE of using random samples x1 , x2 ,....xn taken from Poisson distribution with parameter is, (i)Mode of x1 , x2 ,....xn (ii) Median of x1 , x2 ,....xn (iii) Mean of x1 , x2 ,....xn (iv) None of these 114. Confidence interval for the variance of a normal population involves (i) Std. normal distribution (iii) F- distribution (ii) Chi- distribution (iv) None of these 115. If t1 and t2 be two unbiased estimators of a parameter , then, the efficiency of t1 w.r.to t2 is, V (t1 ) V (t2 ) (iii) V (t1 ) V (t2 ) (iv) V (t2 ) V (t1 ) 116. MLE of in a random sample of size n from U (0, ) is, (i) The sample means (ii) The sample median (iii) The largest order statistics (iv) The smallest order statistics (i) V (t1 ) V (t2 ) (ii) 117. If X is a Poisson variate with parameter , the unbiased estimator based on a single observation x for e 3 is, (i) 3 x (ii) 2 x (iii) 3x (iv) 2 x 118. The difference between estimate and parameter in a sample survey is known as, (i) Non-sampling error (ii) population variance (iii) Sampling error (iv) sampling variance Statistical Inference Page 11 School of Distance Education 119. x follows x y (iii) beta(1/2,1) (iv) None of these x 2 (2), y 2 (1) , x and y are independent, then (i) beta (2,1) (ii) beta(1,1/2) 120. The method of moments was invented by (i) Neyman (ii) Fisher (iii) Karl Pearson (iv) Snedecor 121. A population has a standard deviation of 16. If a sample of size 64 is selected from this population, what is the probability that the sample mean will be within 2 of the population mean? (i) 0.6826 (ii) 0.3413 (iii) -0.6826 (iv) -0.3413 122. If the variance of an estimator attains its Cramer-Rao lower bound for variance, then the estimator is (i) Most efficient (ii) sufficient (iii) unbiased (iv) All the above 123. From the following four unbiased estimators for the population mean, identify the most efficient 1 1 1 1 (i) x1 x2 (ii) x1 3 x2 (iii) 2 x1 2 x2 (iv) x1 5 x2 2 3 4 5 1 x 124. The MLE of using samples x1 , x2 ,....xn from the p.d.f. f ( x ) e is, 2 (i)Mean of x1 , x2 ,....xn (ii) Median of x1 , x2 ,....xn (iii) Mode of x1 , x2 ,....xn (iv) None of these 125. Estimator obtained by the method of MLE, are ----- than the estimator obtained by the method of moments (i) More efficient (iii) Equally efficient 126. (ii) Less efficient (iv) None of these The hypothesis which is under test for possible rejection is (i) Null hypothesis (ii) Alternate hypothesis (iii) Simple hypothesis (iv) None of these 127. A hypothesis contrary to null hypothesis is, (i) Null hypothesis (ii) Alternate hypothesis (iii) Simple hypothesis (iv) None of these 128. Testing of hypothesis was introduced by (i) Fisher (ii) Neyman (iii) Snedecor (iv) Nome of these 129. A statistical hypothesis which completely specifies the population is called, (i) Null hypothesis (ii) Alternate hypothesis (iii) Simple hypothesis (iv) None of these 130. A statistical hypothesis which is not completely specifies the population is called, (i) Null hypothesis (ii) composite hypothesis (iii) Simple hypothesis (iv) None of these 131. The rejection region in testing of hypothesis is known as, (i) Critical region Statistical Inference (ii) normal region (iii) acceptance region (iv) None of these Page 12 School of Distance Education 132. A wrong decision about null hypothesis lead to (i) Type I error (ii) Type II error (iii) both (iv) None of these 133. Significance level is, (i) P(type I error) (ii) P(type II error) (iii) 1- P(type I error) (iv) 1- P(type II error) 134. Power of a test is, (i) P(type I error) (iii) 1- P(type I error) (ii) P(type II error) (iv) 1- P(type II error) 135. Size of a test is (i) P (type I error) (iii) 1- P (type I error) (ii) P (type II error) (iv) 1- P (type II error) 136. Size of a test is also known as, (i) Power (ii) significance level (iii) type I error (iv) type II error 137. The most serious error in testing of hypothesis is, (i) Type I error (ii) Type II error (iii) Both are equally serious (iv) None of these 138. In a coin tossing experiment, let p be the probability of getting a head. The coin is tossed 10 times to test the hypothesis H 0 : p 0.5 against the alternative H1 : p 0.7 . Reject H 0 , if 6 or more tosses out of 10 result in head. Significance level of the test is, 386 186 286 (i) 10 (ii) (iii) 10 (iv) None of these 10 2 2 2 139. Power of a test is e 3 2 , then the probability of type-II error is, 3 3 (i) 1 e 2 (ii) 1 e 2 (iii) e 140. In testing of hypothesis, critical region is 3 2 (iv) None of these (i) Rejection region (ii) Acceptance region (iii) Neutral region (iv) None of these 141. The standard deviation of any statistic is called its, (i) Type II error (ii) Standard error (iii) type I error (iv) None of these 142. Critical region with minimum type II error among all critical regions with a specified significance level is, (i) Powerful critical region (ii) Minimum critical region (iii) Best critical region (iv) None of these 143. Degrees of freedom is related to (i) Number of observations in a set (iii) Number of independent observations in a set 144. (ii) Hypothesis under test (iv) None of these A test which minimizes the power of the test for a fixed significance level is known as (i) Optimum test (ii) randomized test (iii) Likelihood ratio test (iv) None of these Statistical Inference Page 13 School of Distance Education 145. The distribution used for testing mean of a normal population when population variance is unknown with a large sample is, (i) Normal distribution (ii) t distribution (iii) F distribution (iv) None of these 146. In testing of equality of means of two normal population, if 1 , 2 are unknown and in addition it is assumed that = 1 = 2 , then the value of is approximated by, (i) n1S1 n2 S 2 n1 n2 (ii) n12 S12 n2 2 S 2 2 n1 n2 (iii) n1S12 n2 S 2 2 n1 n2 (iv) None of these 147. Test statistics used for testing proportion of a population is, x p0 (i) t n p0 q0 n x p0 n (ii) t p0 q0 / n x p0 n (iii) t p0 q0 n (iv) None of these 148. Chi square test of goodness of fit is introduced by, (i)James Bernoulli (iii) Karl Pearson (ii) Jacob Bernoulli (iv) WS Gosset 149. In Chi square test of goodness of fit, the degrees of freedom of the chi square statistic is n-r-1, where r denotes, (i) Number of parameters are estimated using the observations for the calculation of the theoretical frequencies (ii) Number of observations used for the calculation of the theoretical frequencies (iii) Number of classes of observations (iv) None of these 150. In Chi square test of independence the expected number of observations in i, j th cell is, (i) Nfi. f. j f.. (ii) f i . f. j Nf.. (iii) f i . f. j f.. (iv) None of these 151. For a 2 2 contingency table, where the frequencies are a, b, c and d, as given, the chi square value for testing independence is, (i) ( a b c d )( ad bc )2 ( a b )(c d )(b d )( a c ) ( a b c d )2 ( ad bc ) (iii) ( a b )(c d )(b d )( a c ) (ii) ( a b c d )( ad bc )2 ( a b )(c d )(b d )( a c ) (iv) None of these 152. The theorem supporting the statement that, When the number of sample is large, almost all test statistics follows normal distribution (i)Neyman-Pearson therorem (iii) Bernoullie’s laws Statistical Inference (ii) Central limit theorem (iv) None of these Page 14 School of Distance Education 153. The test statistics used in testing standard deviation of a normal population is, (i) nS 2 n 1 (ii) n 1 S 2 (iii) 02 n2 S 2 02 (iv) None of these 154. Neymann-Pearson lemma is used for obtaining, (i)Most powerful test (iii) A randomized test 155. (ii) An unbiased test (iv) None of these A test is one-sided or two-sided depends on (i) Null hypothesis (ii) Alternate hypothesis (iii) Simple hypothesis (iv) None of these 156. Level of significance lies between, (i) 0 and 1 (ii) -1 and 1 (iii) -3 and 3 (iv)None of these 157. Student’s t test is applicable only when, (i) The variate values are independent (ii) The variable is normally distributed (iii) The sample is small (iv) All the above 158. To test H 0 : 0 , when population SD is unknown and the sample size is small is, (i) t-test (ii) F-test (iii) Normal test (iv) None of these 159. To test H 0 : 0 , when the population SD is known is, (i) t-test (ii) F-test (iii) Normal test (iv) None of these 160. The testing of hypothesis H 0 : k against H1 : k leads to (i) Right tailed test (ii) two tailed test (iii) Left tailed test (iv) None of these 161. The testing of hypothesis H 0 : k against H1 : k leads to (i) Right tailed test (ii) two tailed test (iii) Left tailed test (iv) None of these 162. The testing of hypothesis H 0 : k against H1 : k leads to (i) Right tailed test (ii) two tailed test (iii) left tailed test (iv) None of these 163. The hypothesis that the population variance has a specified value can be tested (i) t-test 164. The statistics freedom, (i) n (ii) F-test 2 (iii) Normal test to test H 0 : 2 (ii) n+1 2 0 (iv) None of these based on a sample of size n, has degrees of (iii) n-1 (iv) None of these 165. Degrees of freedom for a chi-square test of independent with contingency table of order mXn is, (i) mXn (ii) m-1 X n-1 (iii) m+1 X n+1 (iv) None of these 166. Degrees of freedom for a chi square test of independence with contingency table of order 3X4 is, (i) 12 Statistical Inference (ii) 6 (iii) 7 (iv) 20 Page 15 School of Distance Education 167. The testing of hypothesis H 0 : 1 2 against H1 : 1 2 is, (i) O E i 2 i Ei (ii) Oi Ei 2 Ei (iii) Oi Ei Ei 2 (iv) None of these 168. When the degree of freedom increases indefinitely, chi square distribution tends to (i) Normal distribution (ii) t distribution (iii) F distribution (iv) None of these 169. When the set of n expected and observed frequencies are same, the chi square value becomes , (i) Infinity (ii) zero (iii) n (iv) None of these 170. The degree of freedom for statistic- t for paired t-test based on n pairs of observations is, (i) 2(n-1) (ii) n-1 (iii) 2n – 1 (iv) None of these 171. The mean difference between 10 paired observations is 15 and the SD of differences is 5. The value of statistic t is, (i) 27 (ii) 9 (iii) 3 (iv) None of these 172. Which of the following symbols represents a population parameter? (i) SD (ii) σ (iii) r (iv) None of these 173. What does it mean when you calculate a 95% confidence interval? (i) The process you used will capture the true parameter 95% of the time in the long run (ii) You can be “95% confident” that your interval will include the population parameter (iii) You can be “5% confident” that your interval will not include the population parameter (iv) All of the above statements are true 174. What would happen (other things equal) to a confidence interval if you calculated a 99 percent confidence interval rather than a 95 percent confidence interval? (i) It will be narrower (ii) it will not change (iii)The sample size will increase (iv) It will become wider 175. What is the standard deviation of a sampling distribution called? (i) Sampling error (ii) Sample error (iii) Standard error (iv) Simple error 176. A ______ is a subset of a _________. (i) Sample, population (ii) Population, sample (iii)Statistic, parameter (iv) Parameter, statistic 177. A _______ is a numerical characteristic of a sample and a ______ is a numerical characteristic of a population. (i)Sample, population (ii) Population, sample (iii)Statistic, parameter (iv) Parameter, statistic Statistical Inference Page 16 School of Distance Education 178. A sampling distribution might be based on which of the following? (i)Sample means (ii) Sample correlations (iii)Sample proportions (iv) All of the above 179. _________ are the values that mark the boundaries of the confidence interval. (i) Confidence intervals (ii) Confidence limits (iii)Levels of confidence (iv) Margin of error 180. _____ results if you fail to reject the null hypothesis when the null hypothesis is actually false. (i) Type I error (ii) Type II error (iii)Type III error (iv) Type IV error 181. Good way to get a small standard error is to use a ________. (i) Repeated sampling (ii) Small sample (iii)Large sample (iv) Large population 182. The use of the laws of probability to make inferences and draw statistical conclusions about populations based on sample data is referred to as ___________. (i)Descriptive statistics (ii) Inferential statistics (iii)Sample statistics (iv) Population statistics 183. As sample size goes up, what tends to happen to 95% confidence intervals? (i) They become more precise (ii) They become narrower (iii) They become wider (iv) Both (i) and (ii) 184. __________ is the failure to reject a false null hypothesis. (i)Type I error (ii)Type II error (iii) Type A error (iv)Type B error 185. What is the key question in the field of statistical estimation? (i) Based on my random sample, what is my estimate of the population parameter? (ii)Based on my random sample, what is my estimate of normal distribution? (iii)Is the value of my sample statistic unlikely enough for me to reject the null hypothesis? (iv)There is no key question in statistical estimation 186. Cramer Rao lower bound is for finding (i)Unbiased estimator (ii) Consistent estimator (iii) Minimum variance of unbiased estimator (iv) None of these 187. If Tn is a consistent estimator of , then the consistent estimator of 2 is, (i) Tn 2 (ii) Tn (iii) Tn (iv) None of these 188. ---- test is used for testing independence of attributes is a contingency table (i)Normal test Statistical Inference (ii) chi-square test (iii) t-test (iv) None of these Page 17 School of Distance Education 189. The Neymaan-Pearson lemma is used to find ------- for testing simple H 0 against simple H1 (i) Test statistic (ii) best critical region (iii) Power of a test (iv) None of these 190. ----- Distribution is used for constructing confidence interval for the mean of the normal distribution when sample size is large. (i)Normal distribution (ii) t distribution (iii) F distribution (iv) None of these 191. The MLE of in B (1, ) is, (i) x (ii) x 2 (iii) x i i (iv) x 2 i i 192. Fisher-Neyman factorization theorem is used for finding --- estimator (i)Unbiased estimator (ii) Consistent estimator (iii) Minimum variance of unbiased estimator (iv) None of these 193. The value of 2 is zero if and only if, (i) O E i i i (ii) Oi Ei for all i (iii) Oi Ei for all i (iv) None of these i 194. A coin is tossed 600 times and we got 320 heads. Which is test to be used for testing the unbiasedness of the coin? (i)Normal test (ii) chi-square test (iii) t-test (iv) None of these 195. Equality of variances of two normal population is tested by (i)Normal test (ii) chi-square test 196. In paired t test the statistic t (i) t n (ii) t n 1 (iii) t-test u n 1 follows: Su (iii) t n 1 (iv) None of these (iv) None of these 197. In a contingency table the expected frequencies are calculated under ----- hypothesis (i)Null (ii) Alternate (iii) Both (iv) None 198. In a chi square test of independence, we consider the attributes are independent if, (i)The calculated chi square value is equal to table chi square value (ii)The calculated chi square value is greater than the table chi square value (iii)The calculated chi square value is less than the table chi square value (iv)None of these 199. Area of critical region depends up on (i) Type –I error (ii) type –II error (iii) Power (iv) None of these 200. Paired t test is applicable when the observation in the two samples are (i) Paired (ii) correlated (iii) Uncorrelated (iv) None of these *************** Statistical Inference Page 18 School of Distance Education ANSWERS 1. (ii) Statistic 2. (i) Sampling distribution 3. (ii) A parameter 4. (iii) Chi-square 5. (i) 1.2 6. (iv) Can be smaller, larger, or equal to the population mean 7. (iv) Always normal for large sample sizes 8. (iii) Standard error of the mean decreases 9. (ii) Reduce the standard error of the mean to approximately 70% of its current value 10. (ii) Data from the sample is used to estimate the population parameter 11. (ii) 12. (i) 13. (ii) sampling distribution of the mean 14. (iv) None of these 15. (i) 75 16. (iii) Normal distribution 17. (iii) Any sample size t 2 2 t 2n 18. (iv) e 19. (i) 0.5 20. (iv) Sampling distribution of p 21. (iii) Chi-square with 1 d.f. 22. (ii) 0 to 23. (ii) 2(mean) = variance 24. (iii) n 25. (i) 2n 26. (ii) (1 2t ) 27. (ii) (1 2t ) n 2 1 2 28. (i) Chi-square with 7 d.f. 29. (ii) P ( 2 2 ( ) ) . 30. (iv) 2 (n) 31. (ii) Chi-square 32. (iii) Exponential 33. (iii) n-2 34. (i) N(n, 2n ) 35. (ii) + 10.307 36. (ii) X Y n Statistical Inference Page 19 School of Distance Education 37. (iv) Gosset 38. (iii) to 39. (ii) n 1 n 1 2 2 t 2 1 n n n 2 40. (i) 0 ( X ) n 1 S 42. (ii) t – distribution 43. (iii) P(| t | t ) 41. (i) 44. (ii) Distribution with n1 n2 2 d.f. 45. (i) F- distribution with (1,n) d.f. 46. (i) An F- random variable with (1, 1) degree of freedom. 47. (iii) F- distribution with (n,m) d.f. 48. (iii) N(0,1) 49. (i) 3.365. 50. (ii) Function of population values 51. (i) Probability distribution of the sample mean 52. (i) Normal 53. (i) t(1) 54. (ii) Snedecor 55. (ii) 0 to 56. (i) F (n1 1, n2 1) 57. (ii) P( Fn ,n F ) 1 2 58. (i) F = n2 n1 2 n1 n2 2 59. (iii) F (1,1) 60. (iv) P ( X c ) P ( Y 1 ) c 61. (ii) 1 62. (i) 2 n1 63. (ii) less than one 64. (i) t 2 65. (iii) Fisher 66. (ii) estimate 67. (iv) a point estimate 68. (ii) E (t ) 69. (i) E (t ) 70. (iii) Efficient estimator Statistical Inference Page 20 School of Distance Education 71. (i) Point estimator 72. (iii) consistency T (T 1) 73. (iii) n(n 1) 74. (iii) consistency 75. (ii) consistent 76. (ii) consistent 77. (ii) consistent 78. (i) n x i 1 i 79. (i) Unbiased, consistent var(t ) 80. (iv) E (t1 ) var(t1 ) 81. (ii) greater relative efficiency 82. (i) Unbiased 83. (iv) Median of the samples 84. (i) x 85. (ii) 0.5 86. (ii) standard normal table 87. (i)t – table 88. (iii) consistent 89. (iii) both 90. (i) Unbiasedness 91. (i)Fisher-Neyman theorem 92. (ii) biased estimator of 93. (i) Biased 94. (iii) tn and only 95. (i) More efficient 96. (i) Unbiased and efficient 97. (ii) Estimate 98. (ii) M L estimator 99. (iii) either nS 2 100. (ii) n 1 101. (i) V (t1 ) V (t2 ) 102. (iii) a sufficient estimator 103. (i) x i 104. (ii) biased 105. (iii) t 2 is also a consistent estimator of 2 106. (ii) Cramer- Rao inequality 107. (i) Fisher Statistical Inference Page 21 School of Distance Education 108. (i) Normal equations 109. (ii) More efficient 110. (ii) max of x1 , x2 ,....xn 111. (ii) Confidence coefficient 112. (iv) t- distribution 113. (iii) Mean of x1 , x2 ,....xn 114. (ii) Chi- distribution V (t2 ) 115. (iv) V (t1 ) 116. (iii) The largest order statistics 117. (ii) 2 x 118. (iii) Sampling error 119. (ii) beta(1,1/2) 120. (iii) Karl Pearson 121. (i) 0.6826 122. (i) Most efficient 1 123. (i) x1 x2 2 124. (ii) Median of x1 , x2 ,....xn 125. (i) More efficient 126. (i) Null hypothesis 127. (ii) Alternate hypothesis 128. (ii) Neyman 129. (iii) Simple hypothesis 130. (ii) composite hypothesis 131. (i) Critical region 132. (i) Type I error 133. (i) P(type I error) 134. (iv) 1- P(type II error) 135. (i) P (type I error) 136. (ii) significance level 137. (ii) Type II error 386 138. (i) 10 2 3 139. (ii) 1 e 2 140. (i) Rejection region 141. (ii) Standard error 142. (iii) Best critical region 143. (iii) Number of independent observations in a set 144. (iv) None of these 145. (i) Normal distribution Statistical Inference Page 22 School of Distance Education 146. (iii) n1S12 n2 S 2 2 n1 n2 x p0 147. (i) t n p0 q0 n 148. (iii) Karl Pearson 149. (ii) Number of parameters are estimated using the observations for the calculation of the theoretical frequencies f i . f. j 150. (iii) f.. 151. (ii) ( a b c d )( ad bc )2 ( a b )(c d )(b d )( a c ) 152. (ii) Central limit theorem 153. (iv) None of these 154. (i)Most powerful test 155. (i) Null hypothesis 156. (i) 0 and 1 157. (ii)All the above 158. (i) t-test 159. (iii) Normal test 160. (ii) two tailed test 161. (iii) Left tailed test 162. (i) Right tailed test 163. (iv) None of these 164. (iii) n-1 165. (ii) m-1 X n-1 166. (ii) 6 167. (ii) Oi Ei 2 Ei 168. (i) Normal distribution 169. (ii) zero 170. (ii) n-1 171. (ii) 9 172. (ii) σ 173. (iv) All of the above statements are true 174. (iv) It will become wider 175. (iii) Standard error 176. (i) Sample, population 177. (iii)Statistic, parameter 178. (iv) All of the above Statistical Inference Page 23 School of Distance Education 179. (ii) Confidence limits 180. (ii) Type II error 181. (iii)Large sample 182. (ii) Inferential statistics 183. (iv) Both (i) and (ii) 184. (ii)Type II error 185. (i)Based on my random sample, what is my estimate of the population parameter? 186. (iii) Minimum variance of unbiased estimator 187. (i) Tn 2 188. (ii) chi-square test 189. (ii) best critical region 190. (i)Normal distribution 191. K 192. (iv) None of these 193. (ii) Oi Ei for all i 194. (i)Normal test 195. (iv) None of these 196. (ii) t n 1 197. (iii)The calculated chi square value is less than the table chi square value 198. (i)Null 199. (i) Type –I error 200. (i) Paired © Reserved Statistical Inference Page 24