Some normal probability distributions are positively skewed.
When the payoffs are profits, the maximin strategy selects the alternative or act with the
maximum gain.
An interval estimate is a single value used to estimate a population parameter.
To convert a frequency distribution to a relative frequency distribution, divide each
class frequency by the sum of the class frequencies.
Quartiles divide a distribution into 10 equal parts.
If the trend equation is Ŷ = 10 + 100t, the forecasted value increases 100 units for the
next time period, t.
In the final step, using the ratio-to-moving-average method, the total of the 12 modified
means should theoretically be equal to 1,200 because the average of the 12 months is
designated as 100.
Quality control charts indicate whether a production process is in control or out of
control.
The Consumer Price Index measures the change in prices of a fixed market basket of
goods and services from one period to another.
To construct a binomial distribution, it is necessary to know the total number of trials
and the probability of success on each trial.
A state of nature is an uncertain, future event.
The mean of all possible sample means is equal to the population mean.
In the linear trend equation, the letter “b” is the average change in Ŷ for each change
of one unit (either increase or decrease) in t.
The CIA World Factbook cited these numbers for the United States:
‘¢ The birthrate is 13.66 births per 1,000 population.
‘¢ The average life expectancy for females is 81.17 years.
‘¢ Approximately 316.7 million persons reside in the United States.
Each of these numbers is referred to as a statistic.
A correlation matrix can be used to assess multicollinearity between independent
variables.
To employ ANOVA, the populations being studied must be approximately normally
distributed.
For a uniformly distributed random variable, x, P(x) is constant.
One characteristic of the F distribution is that the computed F can only range between
-1 and +1.
The CPI for “educational books and supplies” in June of 2006 was 386.7 (1982-1984 =
100). Interpret this index.
A. There was no significant increase in the price of “educational books and supplies.”
B. The price of “educational books and supplies” increased 386.7 times.
C. If the average price of a textbook in 1982-1984 was $25.00, the CPI for “educational
books and supplies” would predict that the price of the textbook in June 2006 would be
$71.68.
D. If the average price of a textbook in 1982-1984 was $25.00, the CPI for “educational
books and supplies” would predict that the price of the textbook in June 2006 would be
$96.68.
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400
peaches is examined and 50 are found to be defective. What is the z-test statistic?
A. +0.125
B. +0.278
C. -1.645
D. +1.667
The manager of Paul’s fruit and vegetable store is considering the purchase of a new
seedless watermelon from a wholesale distributor. Since this seedless watermelon costs
$4, will sell for $7, and is highly perishable, he only expects to sell between six and
nine of them. What is the opportunity loss for purchasing eight watermelons when the
demand is for nine watermelons?
A. 0
B. 3
C. 4
D. 6
A group of statistics students decided to conduct a survey at their university to find the
average (mean) amount of time students spent studying per week. Assuming a
population standard deviation of three hours, what is the required sample size if the
error should be less than a half hour with a 99% level of confidence?
A. 196
B. 239
C. 15
D. 16
Your favorite soccer team has two remaining matches to complete the season. The
possible outcomes of a soccer match are win, lose, or tie. What is the possible number
of outcomes for the season?
A. 2
B. 4
C. 6
D. 9
Prices and the number produced for selected agricultural items are:
Using the Laspeyres method, what is the price index of agricultural production for 2006
(1980 = 100)?
A. 42.5
B. 129.7
C. 117.1
D. 85.3
Using the following information:
The regression equation is _______.
A. Ŷ = 2.1794 – 12.8094X
B. Ŷ = -12.80894 + 2.1794X
C. 12.8094 X = 2.1794 Ŷ
D. X = -12.8094 + 2.1794 Ŷ
A random sample of 40 companies with assets over $10 million was surveyed and
asked to indicate their industry and annual computer technology expense. The ANOVA
comparing the average computer technology expense among three industries rejected
the null hypothesis. The mean square error (MSE) was 195. The following table
summarized the results:
When comparing the mean annual computer technology expense for companies in the
education and tax services industries, which of the following 95% confidence interval
can be constructed?
A. 13.5 2.026 * 5.78
B. 13.5 2.021 * 5.78
C. 13.5 2.026 * 13.96
D. 13.5 2.021 * 13.96
Consider the following regression equation: Y = 30 + 8X. If SSE = 720 and SS Total =
1,200, then the correlation coefficient is _______.
A. -0.632
B. 0.70
C. 0.632
D. -0.70
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
The best example of an alternate hypothesis for a global test of a multiple regression
model is ______________.
A. H1: β1 = β2 = β3 = β4 = 0
B. H1: β1 ≠β2 ≠β3 ≠β4 ≠0
C. H1: Not all the β’s are equal to 0.
D. If F is less than 20.00, then fail to reject.
A sample of assistant professors on the business faculty at state-supported institutions in
Ohio revealed the mean income to be $72,000 for nine months, with a standard
deviation of $3,000. Using Chebyshev’s theorem, what proportion of the faculty earns
more than $66,000, but less than $78,000?
A. At least 50%
B. At least 25%
C. At least 75%
D. At least 100%
Which measure of central location is used to determine an average annual percent
increase?
A. Arithmetic mean
B. Weighted mean
C. Mode
D. Geometric mean
A multiple regression model includes (X1)(X2). The term is called ________.
A. a dependent variable
B. an interaction
C. an error
D. an intercept
Affirmative action commitments by many organizations have led to an increase in the
number of women in executive positions. Satellite Office Systems has vacancies for
two executives that it will fill from among four women and six men.
What is the probability that at least one woman is selected?
A. 8/15
B. 3/5
C. 2/3
D. 3/4
Twenty economists were sampled and asked to predict if the national economy would
improve during the next 12 months. Eleven of the economists predicted an increase,
two economists predicted no change, and seven economists predicted a decrease in the
economy. Conduct a hypothesis test at the 0.10 significance level to determine if the
majority of economists predict an increase. The test statistic is _______.
A. 0.224
B. 1.179
C. 1.707
D. 0.179
The manager of Paul’s fruit and vegetable store is considering the purchase of a new
seedless watermelon from a wholesale distributor. Since this seedless watermelon costs
$4, will sell for $7, and is highly perishable, he only expects to sell between six and
nine of them. What is the opportunity loss for purchasing seven watermelons when the
demand is for nine watermelons?
A. 0
B. 3
C. 4
D. 6
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 assumed equal. What is the alternate hypothesis?
A. H1: A = B
B. H1: A ≠B
C. H1: A ≤ B
D. H1: A > B
A survey of property owners’ opinions about a street-widening project was taken to
determine if owners’ opinions were related to the distance between their home and the
street. A randomly selected sample of 100 property owners was contacted and the
results are shown next.
What is the expected frequency for people who are in favor of the project and have less
than 45 feet of property foot-frontage?
A. 10
B. 12
C. 35
D. 50
An experiment to determine the most effective way to teach safety principles applied
four different teaching methods. Some employees were given programmed instruction
booklets and worked through the course at their own pace. Other employees attended
lectures. A third group watched a television presentation, and a fourth group was
divided into small discussion groups. A high of 10 was possible. A sample of five tests
was selected from each group. The test grade results were:
At the 0.01 level, what is the critical value?
A. 1.00
B. 1.96
C. 3.24
D. 5.29
The following frequency distribution shows the distribution of delivery times (in days)
for swimstuff.com customer orders during the last month.
How many orders were delivered in less than three days?
The first three class marks for a frequency distribution of “weights of college men”
recorded to the nearest pound are 105, 115, and 125.
What is the class interval?
What is the purpose of an index?
In the linear trend equation, the ____ variable represents the Y-intercept.
If a population is normally distributed, then the sampling distribution of the sample
means will be __________________________.
The following data was collected comparing gasoline prices.
Compute a simple aggregate index comparing gas prices in 2010 to gas prices in 2000.