Download Practice Final Exam Fall 2009

BUSA 3321 Practice Final Exam
1.
The two graphical techniques we usually use to present nominal data are
a. bar chart and histogram
b. pie chart and ogive
c. bar chart and pie chart
d. histogram and ogive
2.
In a positively-skewed distribution,
a. the median equals the mean
b. the median is less than the mean
c. the median is larger than the mean
d. the mean, median, and mode are equal
3.
Which of the following statements is true for the following data values: 7,
5, 6, 4, 7, 8, and 12?
a. The mean, median and mode are all equal
b. Only the mean and median are equal
c. Only the mean and mode are equal
d. Only the median and mode are equal
4.
Which of the following sampling plans does use random methods of
selections?
a. Simple random sampling.
b. Stratified random sampling.
c. Cluster sampling.
d. All of the above.
5.
If two events are mutually exclusive, what is the probability that both occur
at the same time?
a. 0.00
b. 0.50
c. 1.00
d. Cannot be determined from the information given.
6.
If A and B are independent events with P(A) = 0.20 and P(B) = 0.60, then
P(A|B) is:
a. 0.20
b. 0.60
c. 0.40
d. 0.80
7.
The expected number of heads in 100 tosses of an unbiased coin is
a. 25
b. 50
c. 75
d. 100
8.
The variance of a binomial distribution for which n = 100 and p = 0.20 is:
a. 100
b. 80
c. 20
d. 16
9.
What proportion of the data from a normal distribution is within two
standard deviations from the mean?
a. 0.3413
b. 0.4772
c. 0.6826
d. 0.9544
10.
Random samples of size 49 are taken from an infinite population whose
mean is 300 and standard deviation is 21. The mean and standard error of
the sample mean, respectively, are:
a. 300 and 21
b. 300 and 3
c. 70 and 230
d. 49 and 21
11. An infinite population has a mean of 60 and a standard deviation of 8. A
sample of 50 observations will be taken at random from this population.
The probability that the sample mean will be between 57 and 62 is
a. 0.9576
b. 0.9960
c. 0.2467
d. 0.3520
12.
The Central Limit Theorem states that, if a random sample of size n is
drawn from a population, then the sampling distribution of the sample
mean X :
a. is approximately normal if n > 30
b. is approximately normal if n < 30
c. is approximately normal if the underlying population is normal
d. has the same variance as the population
13.
A sample of 250 observations will be selected at random from an infinite
population. Given that the population proportion is .25, the standard error
of the sampling distribution of the sample proportion is:
a. 0.0274
b. 0.5000
c. 0.0316
d. 0.0548
14.
A 98% confidence interval estimate for a population mean  is
determined to be 75.38 to 86.52. If the confidence level is reduced to 90%,
the confidence interval for 
a. becomes wider
b. remains the same
c. becomes narrower
d. None of the above.
15.
To estimate with 99% confidence the mean of a normal population, whose
standard deviation is assumed to be 6 and the maximum allowable
sampling error is assumed to be 1.2, requires a random sample of size
a. 166
b. 165
c. 164
d. 163
16.
Under which of the following circumstances is it impossible to construct a
confidence interval for the population mean?
a. A non-normal population with a large sample and an unknown
population variance
b. A normal population with a large sample and a known population
variance
c. Non-normal population with a small sample and an unknown
population variance
d. A normal population with a small sample and an unknown population
variance
17.
A confidence interval was used to estimate the proportion of international
students. A random sample of 72 students generated the following 90%
confidence interval: (0.438, 0.642). Using the information above, what
size sample would be necessary if we wanted to estimate the true
proportion to within  0.08 using 95% confidence?
a. 105
b. 150
c. 420
d. 597
18.
A university dean is interested in determining the proportion of students
who receive some sort of financial aid. Rather than examine the records
for all the students, the dean randomly selects 200 students and finds that
118 of them are receiving financial aid. The 95% confidence interval for p
is 0.59  0.07. This interval can be interpreted as:
a. we are 95% confident that the true proportion of all students receiving
financial aid is between 0.52 and 0.66.
b. 95% of the students get between 52% and 66% of their tuition paid for
by financial aid.
c. we are 95% confident that between 52% and 66% of the sampled
students receive some sort of financial aid.
d. we are 95% confidence that 59% of the students are on some sort of
financial aid.
19.
A Type I error is committed if we make:
a. a correct decision when the null hypothesis is false
b. a correct decision when the null hypothesis is true
c. incorrect decision when the null hypothesis is false
d. incorrect decision when the null hypothesis is true
20.
In a criminal trial, a Type II error is made when:
a. a guilty defendant is acquitted
b. an innocent person is convicted
c. a guilty defendant is convicted
d. an innocent person is acquitted
21.
Which of the following statements is not true about the level of significance
in a hypothesis test?
a. The larger the level of significance, the more likely you are to reject the
null hypothesis
b. The level of significance is the maximum risk we are willing to accept in
making a Type I error
c. The significance level is also called the  level
d. The significance level is another name for Type II error
22.
Researchers determined that 60 Kleenex tissues is the average number of
tissues used during a cold. Suppose a random sample of 100 Kleenex
users yielded a mean number of 54 tissues used during a cold. Give the
null and alternative hypotheses to determine if the number of tissues used
during a cold is less than 60.
a. H o :   60 and H1 :   60
b. H o :   60 and H1 :   60
c. H o : X  60 and H1 : X  60
d. H o : X  54 and H1 : X  54
23. The p-value criterion for hypothesis testing is to reject the null hypothesis if:
a. p-value = 
b. p-value < 
c. p-value > 
d. -  < p-value < 
24.
A regression analysis between sales (in $1000) and advertising (in $)
resulted in the following least squares line: ŷ = 80,000 + 5x. This implies
that an:
a. increase of $1 in advertising is expected, on average, to result in an
increase of $5 in sales
b. increase of $5 in advertising is expected, on average, to result in an
increase of $5,000 in sales
c. increase of $1 in advertising is expected, on average, to result in an
increase of $80,005 in sales
d. increase of $1 in advertising is expected, on average, to result in an
increase of $5,000 in sales
25.
In the least squares regression line ŷ = 3 - 2x, the predicted value of y
equals:
a. 1.0 when x = -1.0
b. 2.0 when x = 1.0
c. 2.0 when x = -1.0
d. 1.0 when x = 1.0
26.
Testing whether the slope of the population regression line could be zero
is equivalent to testing whether the:
a. sample coefficient of correlation could be zero
b. standard error of estimate could be zero
c. population coefficient of correlation could be zero
d. sum of squares for error could be zero
27.
In a regression problem, if the coefficient of determination is 0.95, this
means that:
a. 95% of the y values are positive
b. 95% of the variation in y can be explained by the variation in x
c. 95% of the x values are equal
d. 95% of the variation in x can be explained by the variation in y
28.
Which of the following assumptions concerning the probability distribution
of the random error term is stated incorrectly?
a. The distribution is normal
b. The mean of the distribution is 0
c. The variance of the distribution increases as x increases
d. The errors are independent
29.
In a simple linear regression problem, r and b1
a. may have opposite signs
b. must have the same sign
c. must have opposite signs
d. must be equal
30.
If the coefficient of correlation is 0.90, then the percentage of the variation
in the dependent variable y that is explained by the variation in the
independent variable x is:
a. 90%
b. 81%
c. 0.90%
d. 0.81%
31.
In order to estimate with 95% confidence the expected value of y for a
given value of x in a simple linear regression problem, a random sample
of 10 observations is taken. Which of the following t-table values listed
below would be used?
a. 2.228
b. 2.306
c. 1.860
d. 1.812
32.
The confidence interval estimate of the expected value of y for a given
value y x, compared to the prediction interval of y for the same given value
of x and confidence level, will be
a. wider
b. narrower
c. the same
d. impossible to know
33.
The width of the confidence interval estimate for the predicted value of y
depends on
a. the standard error of the estimate, s
b. the value of x for which the prediction is being made
c. the sample size
d. All of the above