Download 1. Find the mean for the given sample data. Unless

1. Find the mean for the given sample data. Unless indicated otherwise, round your answer to one more
decimal place than is present in the original data values.
The students in Hugh Logan's math class took the Scholastic Aptitude Test. Their math scores are shown
below. Find the mean score.
536 608 344 340 596
357 343 566 470 482
464.2
476.0
473.7
455.1
2. Find the midrange for the given sample data.
Listed below are the amounts of time (in months) that the employees of an electronics company have been
working at the company. Find the midrange. 12 21 26 37 46 53 61 66 75 76 85 91 132 155
63.5 months
71.5 months
66.9 months
83.5 months
3. Find the standard deviation for the given sample data. Round your answer to one more decimal place
than is present in the original data. 20.0 21.5 27.4 47.3 13.1 11.1
4145.12
37.34
13.11
3285.46
4. Find the indicated probability.
A bag contains 5 red marbles, 3 blue marbles, and 1 green marble. Find P(not blue).
1/3
3/2
6
2/3
5. Find the indicated probability. Round to the nearest thousandth.
In a blood testing procedure, blood samples from 6 people are combined into one mixture. The mixture will
only test negative if all the individual samples are negative. If the probability that an individual sample tests
positive is 0.11, what is the probability that the mixture will test positive?
0.00000177
1.000
0.503
0.497
6. Evaluate the expression. 11 C 4
330
1980
5040
3
7. Provide an appropriate response.
Suppose you pay $3.00 to roll a fair die with the understanding that you will get back $5.00 for rolling a 1
or a 6, nothing otherwise.
What is your expected value?
-$3.00
$3.00
-$1.33
$5.00
8. Assume that a researcher randomly selects 14 newborn babies and counts the number of girls selected, x.
The probabilities corresponding to the 14 possible values of x are summarized in the given table. Answer
the question using the table.
x(girls) P(x) x(girls) P(x) x(girls) P(x)
0 0.000 5 0.122 10 0.061
1 0.001 6 0.183 11 0.022
2 0.006 7 0.209 12 0.006
3 0.022 8 0.183 13 0.001
4 0.061 9 0.122 14 0.000
Find the probability of selecting 2 or more girls.
0.999
0.006
0.001
0.994
9. Determine whether the given procedure results in a binomial distribution. If not, state the reason why.
Choosing 10 marbles from a box of 40 marbles (20 purple, 12 red, and 8 green) one at a time with
replacement, keeping track of the number of red marbles chosen.
Not binomial: there are more than two outcomes for each trial.
Procedure results in a binomial distribution.
Not binomial: the trials are not independent.
Not binomial: there are too many trials.
10. Assume that a procedure yields a binomial distribution with a trial repeated n times. Use the binomial
probability formula to find the probability of x successes given the probability p of success on a single trial.
Round to three decimal places.
n = 4, x = 3, p = 1/6
0.015
0.023
0.012
0.004
11. Use the Poisson model to approximate the probability. Round your answer to four decimal places.
The probability that a call received by a certain switchboard will be a wrong number is 0.02. Use the
Poisson distribution to approximate the probability that among 140 calls received by the switchboard, there
are no wrong numbers.
0.0608
0.1703
0.9392
0.8297
0.0669
12. Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use
your finding to state whether or not the given r represents a significant linear correlation. Use a significance
level of 0.05.
r = 0.843, n = 5
Critical values: r = ±0.878, significant linear correlation
Critical values: r = ±0.950, no significant linear correlation
Critical values: r = 0.950, significant linear correlation
Critical values: r = ±0.878, no significant linear correlation
13. Find the value of the linear correlation coefficient r.
The paired data below consist of the test scores of 6 randomly selected students and the number of hours
they studied for the test.
Hours 5 10 4 6 10 9
Score 64 86 69 86 59 87
0.224
-0.678
0.678
-0.224
14. If z is a standard normal variable, find the probability.
The probability that z is greater than -1.82
0.4656
0.9656
-0.0344
0.0344
15. Solve the problem.
A bank's loan officer rates applicants for credit. The ratings are normally distributed with a mean of 200
and a standard deviation of 50. If 40 different applicants are randomly selected, find the probability that
their mean is above 215.
0.0287
0.1179
0.4713
0.3821
16. The given values are discrete. Use the continuity correction and describe the region of the normal
distribution that corresponds to the indicated probability.
The probability of no more than 75 defective CD's
The area to the right of 75.5
The area to the left of 75
The area to the left of 74.5
The area to the left of 75.5
17. Use the normal distribution to approximate the desired probability.
Find the probability that in 200 tosses of a fair die, we will obtain at most 30 fives.
0.1871
0.4936
0.2946
0.3229
18. Assume that a sample is used to estimate a population proportion p. Find the margin of error E that
corresponds to the given statistics and confidence level. Round the margin of error to four decimal places.
In a random sample of 184 college students, 97 had part-time jobs. Find the margin of error for the 95%
confidence interval used to estimate the population proportion.
0.0721
0.00266
0.126
0.0649
19. Use the given degree of confidence and sample data to construct a confidence interval for the
population proportion p.
n = 125, x = 72; 90% confidence
0.507 < p < 0.645
0.503 < p < 0.649
0.506 < p < 0.646
0.502 < p < 0.650
20. Use the given data to find the minimum sample size required to estimate the population proportion.
Margin of error: 0.015; confidence level: 96%; p (with a cone over it) and q (with a cone over it) unknown
6669
3667
4519
4670
21. Solve the problem. Round the point estimate to the nearest thousandth.
50 people are selected randomly from a certain population and it is found that 13 people in the sample are
over 6 feet tall. What is the point estimate of the proportion of people in the population who are over 6 feet
tall?
0.50
0.26
0.19
0.74
22. Use the confidence level and sample data to find a confidence interval for estimating the population
(mu). Round your answer to the same number of decimal places as the sample mean.
A random sample of 130 full-grown lobsters had a mean weight of 21 ounces and a standard deviation of
3.0 ounces. Construct a 98% confidence interval for the population mean mu.
21 oz < mu < 23 oz
20 oz < mu < 22 oz
20 oz < mu < 23 oz
19 oz < mu < 21 oz
23. Assume that the data has a normal distribution and the number of observations is greater than fifty. Find
the critical z value used to test a null hypothesis.
α= 0.05 for a left-tailed test.
-1.96
±1.96
±1.645
-1.645
24. Find the value of the test statistic z using z = the formula is z= p(with a cone over it) –p over pq over n
squared
The claim is that the proportion of accidental deaths of the elderly attributable to residential falls is more
than 0.10, and the sample statistics include n = 800 deaths of the elderly with 15% of them attributable to
residential falls.
3.96
-3.96
4.71
-4.71
25. Use the given information to find the P-value. Also, use a 0.05 significance level and state the
conclusion about the null hypothesis (reject the null hypothesis or fail to reject the null hypothesis).
The test statistic in a right-tailed test is z = 1.43.
0.1528; fail to reject the null hypothesis
0.1528; reject the null hypothesis
0.0764; fail to reject the null hypothesis
0.0764; reject the null hypothesis