A test statistic is a value computed from sample information that is used to test the null
hypothesis.
When sampling is done without replacement and the outcomes are measured as either a
success or failure, the hypergeometric distribution should be applied.
The Paasche method uses the amounts consumed in the base period, q0, as weights to
determine a price index.
A dot plot is an easy way to represent the relationship between two variables.
Categorizing voters as Democrats, Republicans, and Independents is an example of
interval level measurement.
Bayes’ theorem is a method to revise the probability of an event given additional
information.
In regression analysis, error is defined as .
The pooled estimate of the proportion is found by dividing the total number of samples
by the total number of successes.
In a sample of 10 people, 3 persons earn $8 an hour, 6 earn $9 an hour, and 1 earns $12
an hour. The weighted mean hourly wage is $9.
When a blocking effect is included in an ANOVA, the analysis is more likely to detect
differences in the treatment means.
The probability of a Type II error is represented by the Greek symbol, β.
For the hypothesis test, with n1 = 10 and n2 = 10, the F-test statistic is 2.56.
At the 0.01 level of significance, we would reject the null hypothesis.
If the size of a sample equals the size of the population, we would not expect any error
in estimating the population parameter.
In acceptance sampling, if the number of defects in a sample is less or equal to the
acceptance number, then the incoming lot is accepted.
Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones
Brothers has maintained careful records regarding the time to prepare a return. The
mean time to prepare a return is 90 minutes and the standard deviation of this
distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed
regarding the preparation time. What is the standard error of the mean?
A. 14 minutes
B. 140 minutes
C. 1.4 minutes
D. 90 minutes
The ABCD football association is considering a Super Ten Football Conference. The
top 10 football teams in the country, based on past records, would be members of the
Super Ten Conference. Each team would play every other team in the conference during
the season and the team winning the most games would be declared the national
champion. How many games would the conference commissioner have to schedule
each year? (Remember, Oklahoma versus Michigan is the same as Michigan versus
Oklahoma.)
A. 45
B. 50
C. 125
D. 14
A population has a known standard deviation of 25. A simple random sample of 49
items is taken from the selected population. The sample mean (x-bar) is 300. What is
the margin of error at the 95% confidence level?
A. 8
B. 293
C. 7
D. 308
A multiple regression model includes the term (X1)(X2). If the hypothesis is that the
term’s regression coefficient is NOT rejected, what is a valid conclusion?
A. The independent variables are correlated.
B. There is only one independent variable in the regression model.
C. The effect of X1 on the dependent variable is independent of the value of X2.
D. The effect of X1 on the dependent variable depends on the value of X2.
In the Kruskal-Wallis test for the following data, what is the sum of the ranks for
Sample 3?
A. 9
B. 80
C. 3
D. 23
If an average of 12 customers is served per hour, what is the probability that the next
customer will arrive in 6 minutes or less?
A. 0.61
B. 0.30
C. 0.70
D. 0.39
If an average of 12 customers is served per hour, what is the probability that the next
customer will arrive in 3 minutes or less?
A. 0.55
B. 0.30
C. 0.45
D. 0.39
A student was interested in the cigarette smoking habits of college students and
collected data from an unbiased random sample of students. The data is summarized in
the following table:
What type of chart best represents relative class frequencies?
A. Box plot
B. Pie chart
C. Scatter plot
D. Frequency polygon
A group of women tried five brands of fingernail polish and ranked them according to
preference. What level of measurement is this?
A. Nominal
B. Ordinal
C. Interval
D. Ratio
A monthly price index that describes the changes in prices from one period to another
for a “market basket” of goods and services is known as the ______________.
A. Laspeyres index
B. deflator index
C. Consumer Price Index
D. Paasche index
If a company reports that its quarterly earnings will be between $100 million and $125
million depending on the consumer demand, consumer demand is an example of
________ variation.
A. chance
B. external
C. assignable
D. standard
A survey of an urban university (population of 25,450) showed that 870 of 1,100
students sampled supported a fee increase to fund improvements to the student
recreation center. Using the 99% level of confidence, what is the confidence interval for
the proportion of students supporting the fee increase?
A. [0.751, 0.829]
B. [0.759, 0.823]
C. [0.767, 0.814]
D. [0.771, 0.811]
An electronics firm sells four models of stereo receivers, three amplifiers, and six
speaker brands. When the four types of components are sold together, they form a
‘system.” How many different systems can the electronics firm offer?
A. 36
B. 18
C. 72
D. 144
Recently, students in a marketing research class were interested in the driving behavior
of students. Specifically, the marketing students were interested in finding out if
exceeding the speed limit was related to social activity. They collected the following
responses from 100 randomly selected students:
The degrees of freedom for the analysis are ________.
A. 1
B. 2
C. 3
D. 4
For a binomial distribution, the mean is 4.0 and n = 8. What is π for this distribution?
A. 0.5
B. 1.00
C. 4.0
D. 0.1
The average score of 100 students taking a statistics final was 70, with a standard
deviation of 7. Assuming a normal distribution, what test score separates the top 5% of
the students from the lower 95% of the students?
A. 81.55
B. 90.00
C. 83.72
D. 78.96
The Durbin-Watson statistic is used to analyze ___________.
A. multicollinearity
B. homoscedasticity
C. autocorrelation
D. variance inflation
For a data set, half of the observations are always greater than the ____.
A. Median
B. Mode
C. Mean
D. Standard deviation
A random sample of 30 executives from companies with assets over $1 million was
selected and asked for their annual income and level of education. The ANOVA
comparing the average income among three levels of education rejected the null
hypothesis. The mean square error (MSE) was 243.7. The following table summarized
the results:
Based on the comparison between the mean annual incomes for executives with
undergraduate and master’s degrees or more, ________________.
A. a confidence interval shows that the mean annual incomes are not significantly
different
B. the ANOVA results show that the mean annual incomes are significantly different
C. a confidence interval shows that the mean annual incomes are significantly different
D. the ANOVA results show that the mean annual incomes are not significantly
different
A hypothesis test that a rank correlation coefficient is zero is conducted at the 5% level
of significance. If the correlation coefficient is 0.50 for a sample of 15 observations,
what is the computed value of the t statistic?
A. 0.456
B. 6.08
C. 2.082
D. 2.2361
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. Based on maximin, maximax, and minimax regret strategies, what
alternative is selected?
A. Order 6
B. Order 7
C. Order 8
D. Order 9
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 payoff value for the purchase of nine watermelons when the
demand is for nine watermelons?
A. 6
B. 13
C. 20
D. 27
In the general multiple regression equation, which of the following variables represents
the Y-intercept?
A. b1
B. X1
C. Ŷ
D. a
The test statistic for a goodness-of-fit test for unequal expected frequencies is a
__________ statistic.
A company wants to study the effect of an employee’s length of employment on their
number of workdays absent. The results of the regression analysis follow.
What is the standard error of estimate?
A major distributor buys shoes from a supplier. The distributor randomly samples the
shoes to inspect for quality. The distributor’s specifications state that a delivery of 50
pairs of shoes will be accepted only if the number of defective pairs of shoes in a
sample of 5 pairs is two or less. Based on the sampling plan, what is the probability of
accepting the delivery of 50 pairs of shoes if the actual percent defective is 0.40?
After arriving at the university student medical clinic, the waiting times to receive
service after checking-in follow an exponential distribution with a mean of 10 minutes.
Fifty percent of the students wait less than how many minutes?
If the sample correlation coefficient, r, is -0.96, the dependent variable ________ as the
independent variable increases.
The ______ test statistic is used to test the significance of the Spearman coefficient of
rank correlation.
Thirty-six items are randomly selected from a population of 150 items. The sample
mean is 25 and the sample standard deviation is 3. What is the finite population
correction factor?
When testing a goodness-of-fit null hypothesis, and there are extremely large
differences between observed and expected frequencies, the null hypothesis should be
___________.