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The regression equation is Ŷ = 29.29 - 0.96X, the sample size is 8, and the standard
error of the slope is 0.22. What is the critical value to test the significance of the slope
at the 0.01 significance level?
A. z = +2.576
B. t = +3.707
C. t = +3.355
D. t = 3.707
For the standard normal distribution, the z score that corresponds with the 85th
percentile is ________.
A sales manager for an advertising agency believes that there is a relationship between
the number of contacts that a salesperson makes and the amount of sales dollars earned.
A regression ANOVA shows the following results:
What is the value of the standard error of estimate?
A. 9.310
B. 8.778
C. 8.328
D. 86.68
A dot plot is useful for showing the range of the data.
What is the range of values for the coefficient of determination?
A. -1 to +1 inclusive
B. -100% to +100% inclusive
C. -100% to 0% inclusive
D. 0% to 100% inclusive
A manufacturer of automobile transmissions uses three different processes.
Management ordered a study of the production costs to see if there is a difference
among the three processes. A summary of the findings is shown next.
In an ANOVA table, what are the degrees of freedom for the error source of variation?
A. 3
B. 10
C. 27
D. 30
A bottling company offers three kinds of delivery service: instant, same day, and within
five days. The profit per delivery varies according to the kind of delivery. The profit for
an instant delivery is less than the other kinds because the driver has to go directly to a
grocery store with a small load and return to the bottling plant. To find out what effect
each type of delivery has on the profit picture, the company summarized the data in the
following table based on deliveries for the previous quarter.
What is the weighted mean profit per delivery?
A. $72
B. $110
C. $142
D. $97
Based on the regression equation, we can _______________.
A. Predict the value of the dependent variable given a value of the independent variable
B. Predict the value of the independent variable given a value of the dependent variable
C. Measure the association between two variables
D. Measure cause and effect
A company is studying the number of monthly absences among its 125 employees. The
following probability distribution shows the likelihood that people were absent 0, 1, 2,
3, 4, or 5 days last month.
What is the mode of the distribution?
A. 0.72 days
B. 2.5 days
C. 0 days
D. 3 days
When determining how well an observed set of frequencies fit an expected set of
frequencies, what is the test statistic?
A. F-statistic
B. t-statistic.
C. statistic
D. z-statistic
Refer to the following information from a frequency distribution for "heights of college
women" recorded to the nearest inch: the first two class midpoints are 62.5" and 65.5".
What is the class interval?
A. 1"
B. 2"
C. 2.5"
D. 3"
Given the least squares regression equation, Ŷ = 1,202 + 1,133X, when X = 3, what does
Ŷ equal?
A. 5,734
B. 8,000
C. 4,601
D. 4,050
Ten experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their
ratings were: 34, 35, 41, 28, 26, 29, 32, 36, 38, and 40. What is the mean deviation of
the ratings?
A. 8.00
B. 4.12
C. 12.67
D. 0.75
A board of directors consists of eight men and four women. A four-member search
committee is randomly chosen to recommend a new company president. What is the
probability that all four members of the search committee will be women?
A. 1/120 or 0.00083
B. 1/16 or 0.0625
C. ⅛ or 0.125
D. 1/495 or 0.002
A recent study of the relationship between social activity and education for a sample of
corporate executives showed the following results.
Using 0.05 as the significance level, what is the critical value for the test statistic?
A. 9.488
B. 5.991
C. 7.815
D. 3.841
Two normal distributions are compared. One has a mean of 10 and a standard deviation
of 10. The second normal distribution has a mean of 10 and a standard deviation of 2.
Which of the following is true?
A. The locations of the distributions are different.
B. The distributions are from two different families of distributions.
C. The dispersions of the distributions are different.
D. The dispersions of the distributions are the same.
Which statement is correct about the F distribution?
A. Cannot be negative
B. Cannot be positive
C. Is the same as the t distribution
D. Is the same as the z distribution
A company is researching the effectiveness of a new website design to decrease the
time to access a website. Five website users were randomly selected, and their times (in
seconds) to access the website with the old and new designs were recorded. To compare
the times, they computed (new website design time - old website design time). The
results follow.
For a 0.01 significance level, what is the decision regarding the hypothesis that the
training was effective in improving customer relationships?
A. Reject the null hypothesis and conclude that the new design reduced mean access
times.
B. Reject the null hypothesis and conclude that the new design did not reduce mean
access times.
C. Fail to reject the null hypothesis.
D. Fail to reject the null hypothesis and conclude that the mean access times are
inaccurate.
A company is researching the effectiveness of a new website design to decrease the
time to access a website. Five website users were randomly selected, and their times (in
seconds) to access the website with the old and new designs were recorded. To compare
the times, they computed (new website design time - old website design time). The
results follow.
What is the value of the test statistic?
A. 2.256
B. 1.895
C. 3.747
D. 2.447
What is the relationship among the mean, median, and mode in a symmetric
distribution?
A. They are all equal.
B. The mean is always the smallest value.
C. The mean is always the largest value.
D. The mode is the largest value.
The following correlations were computed as part of a multiple regression analysis that
used education, job, and age to predict income.
Which is the dependent variable?
A. Income
B. Age
C. Education
D. Job
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches
41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that
they watch the late evening news on this local CBS station. What is the critical value if
α = 0.01?
A. +2.576
B. +2.326
C. 2.576
D. -2.326
A survey of households in a small town showed that in 500 of 1,200 sampled
households, at least one member attended a town meeting during the year. Using the
95% level of confidence, what is the confidence interval for the proportion of
households represented at a town meeting?
A. [0.417, 0.427]
B. [0.389, 0.445]
C. [0.400, 0.417]
D. [0.417, 0.445]
A regression analysis yields the following information:
; n = 10; sy∙x = 1.66; ΣX = 32; ΣX2 = 134;
Compute the 95% confidence interval when X = 4.
A. 0.0, 4.05
B. 4.15, 12.25
C. 2.67, 5.33
D. 6.842, 9.497
The annual dividend rates for a random sample of 16 companies in three different
industries, utilities, banking, and insurance were recorded. The ANOVA comparing the
mean annual dividend rate among three industries rejected the null hypothesis that the
dividend rates were equal. The Mean Square Error (MSE) was 3.36. The following
table summarized the results:
Based on the comparison between the mean annual dividend rate for companies in
utilities and banking, the 95% confidence interval shows an interval of 1.28 to 6.28 for
the difference. This result indicates that _____________________.
A. There is no significant difference between the two rates
B. The interval contains a difference of 5.00
C. The annual dividend rate in the utilities industry is significantly less than the annual
dividend rate in the banking industry
D. The annual dividend rate in the banking industry is significantly less than the annual
dividend rate in the utilities industry
Two accounting professors decided to compare the variance of their grading procedures.
To accomplish this, they each graded the same 10 exams, with the following results:
What are the degrees of freedom for the numerator of the F ratio?
A. 8
B. 9
C. 10
D. 18
What is the critical value at the 0.05 level of significance for a goodness-of-fit test if
there are six categories?
A. 3.841
B. 5.991
C. 7.815
D. 11.070
In the least squares equation, Ŷ = 10 + 20X the value of 20 indicates ____________.
A. The Y-intercept increases by 20 units for each unit increase in X
B. That Y increases by 20 units for each unit increase in X
C. That X increases by 20 units for each unit increase in Y
D. The error in prediction
For a uniformly distributed random variable, x, P(x) = 1/(b - a).
The tread life of tires mounted on light-duty trucks follows the normal probability
distribution with a mean of 60,000 miles and a standard deviation of 4,000 miles.
Suppose we select a sample of 40 tires and use a simulator to determine the tread life.
What is the likelihood of finding that the sample mean is between 59,050 and 60,950?
A. 0.4332
B. 0.8664
C. 1.00
D. Very likely
When the order of a set of objects selected from a single group is important, this is
called ________.
For the past week, a company's common stock closed with the following prices: $61.5,
$62, $61.25, $60.875, and $61.5. What was the price range?
A. $1.250
B. $1.750
C. $1.125
D. $1.875
Categorizing students as freshmen, sophomores, juniors, and seniors is an example of
the ______________ level of measurement.
The prime rate of interest is an example of a(n) ______________ level of measurement.
A population consists of 15 values. How many samples of size 10 are possible?
A class relative frequency represents a __________ of the total observations in the
class.
A sample revealed that the ages of a popular group of musicians are 36, 29, 37, 32, 36,
and 75. What is the median age?
The only time the variance equals the standard deviation is when _____________.
A multiple regression analysis showed the following ANOVA table result.
Based on the information in the ANOVA, how many independent variables were
included in the multiple regression analysis?
For the following data, find the information required to construct a box plot.
A ___________ uses dots to show frequencies.
LongLast Inc. produces car batteries. The mean life of these batteries is 60 months. The
distribution of the battery life closely follows the normal probability distribution with a
standard deviation of eight months. As part of its testing program, LongLast tests a
sample of 25 batteries. What is the standard error of the mean?
In a study of protein breakfast bars, five bars from each of three brands were tested to
see if the mean amount of protein per bar differs among the brands. If the sum of
squares for the brands is 0.07, the mean square for brands is _____.
Auditors may select every 20th file starting with the 5th file in the top drawer. Then, file
numbers 25, 45, 65, 85, . . . are selected. This type of sampling is called ___________.
A telemarketing firm is monitoring the performance of its employees based on the
number of sales per hour. One employee had the following sales for the last 19 hours.
What is the median for the distribution of number of sales per hour?
Sampling is required when crash testing cars because the products are __________.
We are interested in knowing if the following frequency distribution is normally
distributed. The population mean and standard deviation of the data are 600 and 160,
respectively.
To test the hypothesis that the frequency distribution is normally distributed, what is the
value of the chi-square critical value at the .05 level of significance?
The _________ approach to probability is based on a person's belief, opinion, or
judgment.
To compare the effect of weather on sales of soft drinks, a distributor surveyed people
in two regions of the country and asked if they purchased soft drinks in the last month.
The following are the results. The distributor would like to know if there is a difference
in sales between the two regions?
What is the proportion of people who purchased soda in Region A?
The paired t test is especially appropriate when the two samples are ________.
