In an ANOVA table for a multiple regression analysis, the regression mean square is
__________.
A. The treatment sum of squares divided by the regression degrees of freedom
B. n – (k + 1)
C. The regression sum of squares divided by the regression degrees of freedom
D. The total sum of squares divided by the regression degrees of freedom
For the following distribution:
What is the mean of the distribution?
A. 1
B. 2.5
C. 1.604
D. 3
Based on the Empirical Rule, what percent of the observations will lie between plus or
minus two standard deviations from the mean?
A. 95%
B. 5%
C. 68%
D. 2.5%
As the size of the sample increases, what happens to the shape of the distribution of
sample means?
A. It cannot be predicted in advance.
B. It approaches a normal distribution.
C. It is positively skewed.
D. It is negatively skewed.
If 20 out of 50 students sampled live in a college dormitory, what is the estimated
proportion of students at the University living in a dormitory?
A. 0.20
B. 0.40
C. 0.50
D. 0.60
For any data set, which measures of central location have only one value?
A. Mode and median
B. Mode and mean
C. Mode and standard deviation
D. Mean and median
For a normal distribution, what is the likelihood (expressed as a percentage) that a
random variable is within plus and minus two standard deviations of the mean?
A. 68.26%
B. 99.74%
C. 34.13%
D. 95.44%
A university surveyed recent graduates of the English Department for their starting
salaries. Four hundred graduates returned the survey. The average salary was $25,000,
with a standard deviation of $2,500. What is the best point estimate of the population
mean?
A. $25,000
B. $2,500
C. $400
D. $62.5
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 coefficient of correlation?
A. +0.6317
B. +0.9754
C. -0.9754
D. +0.9513
A manufacturer of automobile transmissions uses two different processes. Management
ordered a study of the production costs to see if there is a difference between the two
processes. A summary of the findings is shown next.
What is the critical value of F at the 5% level of significance?
A. 19.45
B. 3.00
C. 4.41
D. 4.38
A coin is tossed four times. The following table summarizes the experiment. What is the
following table called?
A. Probability distribution
B. Cumulative frequency distribution
C. Standard deviation
D. Frequency table
In the general multiple regression equation, which of the following variables represents
the Y-intercept?
A. b1
B. X1
C. Ŷ
D. a
A tire manufacturer advertises, “the median life of our new all-season radial tire is
50,000 miles. An immediate adjustment will be made on any tire that does not last
50,000 miles.” You purchased four of these tires. What is the probability that all four
tires will wear out before traveling 50,000 miles?
A. 1/10 or 0.10
B. or 0.25
C. 1/64 or 0.0156
D. 1/16 or 0.0625
Suppose a research firm conducted a survey to determine the mean amount steady
smokers spend on cigarettes during a week. A sample of 100 steady smokers revealed
that the sample mean is $20 and the sample standard deviation is $5. What is the
probability that a sample of 100 steady smokers spend between $19 and $21?
A. 0.4772
B. 0.0228
C. 0.9544
D. 1.0000
A gumball machine is filled with 50 black, 150 white, 100 red, and 100 yellow
gumballs that have been thoroughly mixed. Sue and Jim each purchased one gumball.
What is the likelihood both Sue and Jim get red gumballs?
A. 0.50
B. 0.062
C. 0.33
D. 0.75
The Equal Employment Opportunity Act requires employers to classify their employees
by gender and national origin. Which level of measurement is this?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
What does the correlation matrix for a multiple regression analysis contain?
A. Multiple correlation coefficients
B. Simple correlation coefficients
C. Multiple coefficients of determination
D. Multiple standard errors of estimate
The coefficient of determination measures the proportion of ____________.
A. Explained variation relative to total variation
B. Variation due to the relationship among variables
C. Error variation relative to total variation
D. Variation due to regression
A national manufacturer of ball bearings is experimenting with two different processes
for producing precision ball bearings. It is important that the diameters be as close as
possible to an industry standard. The output from each process is sampled and the
average error from the industry standard is measured in millimeters. The results are
presented next.
The researcher is interested in determining whether there is evidence that the two
processes yield different average errors. The population standard deviations are
unknown but are assumed equal. If we test the null hypothesis at the 1% level of
significance, what is the decision?
A. Reject the null hypothesis and conclude the means are different.
B. Reject the null hypothesis and conclude the means are the same.
C. Fail to reject the null hypothesis.
D. Fail to reject the null hypothesis and conclude the means are different.
The time to fly between New York City and Chicago is uniformly distributed with a
minimum of 120 minutes and a maximum of 150 minutes. What is the probability that a
flight is more than 140 minutes?
A. 1.00
B. 0.5
C. 0.333
D. 0.00
The following is a binomial probability distribution with n = 3 and π = 0.20.
The variance of the distribution is _________.
A. 1.5
B. 3.0
C. 0.69
D. 0.48
In multiple regression analysis, before testing the significance of the individual
regression coefficients, _______________.
A. The intercept must equal 0
B. The multiple standard error of the estimate must be less than the error mean square
C. The null hypothesis that all regression coefficients equal zero must NOT be rejected
D. The null hypothesis that all regression coefficients equal zero must be rejected
To determine if a set of ungrouped raw data is normally distributed, the null hypothesis
is ________________.
A. The data are normally distributed
B. The data are not normally distributed
C. The Anderson-Darling test is greater than 0.0
D. The Anderson-Darling test equal to 0.0
A recent study focused on the number of times men and women send a Twitter message
in a day. The information is summarized next.
At the .01 significance level, is there a difference in the mean number of times men and
women send a Twitter message in a day? What is the p-value for this hypothesis test?
A. 0.0500
B. 0.0164
C. 0.0001
D. 0.0082
In a uniform distribution, with a minimum, a, and maximum, b, the probability that the
random variable, x, is between a and (b – a)/2 is ___________.
A sample mean is the best point estimate of _______.
A. The population standard deviation
B. The population median
C. The population mean
D. The sample standard deviation
A hypothesis regarding the weight of newborn infants at a community hospital is that
the mean is 6.6 pounds. A sample of seven infants is randomly selected and their
weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the
sample variance?
A. 1.177
B. 6.6
C. 1.385
D. 7.6
When data is collected using a quantitative, ratio variable, what is true about a
frequency distribution that summarizes the data?
A. Upper and lower class limits must be calculated.
B. A pie chart can be used to summarize the data.
C. Number of classes is equal to the number of variable’s values.
D. The “5 to the k rule” can be applied.
Which measures of central location are not affected by extremely small or extremely
large values?
A. Mean and median
B. Mean and mode
C. Mode and median
D. Standard deviation and mean
A personnel manager is concerned about absenteeism. She decides to sample employee
records to determine if absenteeism is distributed evenly throughout the six-day
workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the
week. The 0.01 level is to be used. The sample results are:
What is the calculated value of chi-square?
A. 1.0
B. 0.5
C. 0.8
D. 8.0
A machine is set to fill the small-size packages of M&M candies with 56 candies per
bag. A sample revealed: three bags of 56, two bags of 57, one bag of 55, and two bags
of 58. To test the hypothesis that the mean candies per bag is 56, how many degrees of
freedom are there?
A. 9
B. 1
C. 8
D. 7
A company was studying the demographics of their customers. As part of the study,
they collected the following variables: gender, marital status, credit rating (low,
medium, high), annual income, and age. Label each variable as qualitative or
quantitative, discrete or continuous, and nominal, ordinal, interval, or ratio.
If the null hypothesis is true and the researchers reject it, a ________ error has been
made.
If n = 900 and π = , the variance of this binomial distribution is ______. ⅓
The value that occurs most often in a set of data is called the ________.
An assumption of linear regression states that for each value of X, there is a group of Y
values that are statistically __________________ and normally distributed about the
regression line.
In relative terms, a _______ standard deviation leads to a narrower confidence interval.
Describe the difference between a population and a sample.
In a positively skewed distribution, the 50th percentile is the same as the
______________.
The relationship between the mean and median in a negatively skewed distribution
would be that the _____________.
To construct a bar chart, the class frequencies are plotted on the _________.
A __________ analysis is used to develop an equation that predicts an outcome based
on two or more independent variables.
There are 10 flights from Minneapolis to St. Cloud each day. The probability that any
one flight is late is 0.05. Using the binomial probability formula, what is the probability
that none are late?
In multiple regression, the __________ accounts for the variance of additional
independent variables.
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 a part of its testing program, LongLast tests a
sample of 25 batteries. What proportion of the samples will have a mean useful life
between 58 and 62 months?