For a one-tailed test with a 0.05 level of significance, the critical z statistic is 1.645, but
the critical t statistic is 1.96.
An expected opportunity loss can only be greater than or equal to zero.
The probability of a particular outcome must always be between 0.0 and 1.0 inclusive.
Which of the following statements regarding the coefficient of correlation is TRUE?
A. It ranges from 0.0 to +1.0 inclusive.
B. It describes the relationship between two variables.
C. A value of 0.00 indicates two variables are related.
D. It is calculated as the square of the slope.
By definition, the decision maker has no control over the states of nature.
In the sampling distribution of the sample means, the standard error of the mean will
vary according to the size of the sample. As the sample size, n, gets larger, the
variability of the sampling distribution of the means gets larger.
In a linear trend equation, t is a coded value that corresponds with a time period in a
time series.
The branch of mathematics used to facilitate the collection, organization, presentation,
analysis, and interpretation of numerical information is referred to as statistics.
An example of a weight used in the calculation of a weighted index is quantity
consumed in a base period.
A survey of 50 retail stores revealed that the average price of a microwave was $375
with a sample standard deviation of $20. Assuming the population is normally
distributed, what is the 99% confidence interval to estimate the
The chi-square distribution is positively skewed.
The z-scores for X values greater than the mean are negative.
Some important uses of the chi-square include testing for the association of two
categorical variables.
To apply the Kruskal-Wallis test, the samples selected from the populations must be
dependent.
The Bureau of the Census reported that the farm population dropped from 30.5 million
in 1940 to 6.5 million in 1999. What is the index for 1999 based on 1940?
A. 469.7
B. 100.0
C. 21.3
D. 78.7
Income is a variable often used in business and economics. Income is an example of a
variable that uses the:
A. Ordinal scale
B. Nominal scale
C. Ratio scale
D. Interval scale
The number of workers calling in sick during any particular week is considered to be
_______________ data.
A quality control chart is used to monitor the customer wait time at a local call center.
Sample means of five times are averaged and plotted over time. The last five sample
means show a trend of decreasing sample means. The process is:
A. out of control.
B. in control.
C. improving.
D. showing chance variation.
What is the null hypothesis to test the significance of the slope in a regression equation?
A. H0: β = 0
B. H0: β ≠0
C. H0: β ≤ 0
D. H0: β ≥ 0
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 25% of
the students from the lower 75% of students?
A. 70.00
B. 74.69
C. 65.31
D. 75.25
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. What is the computed value of t?
A. +2.797
B. -1.000
C. -3.299
D. 0.5938
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.
What is the independent variable?
A. Salesperson
B. Number of contacts
C. Amount of sales
D. Sales manager
Control charts are used to determine if a process is:
A. in or out of control.
B. measurable.
C. fixable.
D. testable.
A group of employees of Unique Services will be surveyed about a new pension plan.
In-depth interviews with each employee selected in the sample will be conducted. The
employees are classified as follows:
What is the probability that the first person selected is a supervisor and in management?
A. 0.00
B. 0.06
C. 0.15
D. 0.21
The Spearman coefficient of rank correlation is:
A. a measure of correlation used to determine whether several population means are
equal.
B. describes the association between sets of ranked data.
C. a measure of correlation based on the sign of a difference between two related
observations.
D. is a goodness-of-fit test used to test for normality.
A portion or part of a population is called a:
A. Random survey
B. Sample
C. Tally
D. Frequency distribution
A subassembly is inspected and the number of defects recorded. A new group of
assemblers began work Monday morning. The number of defects per subassembly for
the first 10 they produced was: 3, 2, 0, 5, 4, 6, 0, 7, 7, and 6. What are the upper and
lower limits for the c-bar chart?
A. 15 and 0
B. 10 and 0
C. 1.12 and 0
D. 6 and -2
A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces.
Then, once the machine is running, a sample of six tubes is taken every three hours and
weighed with the following results:
What is the range of the samples at 4 pm?
A. 0.05
B. 0.06
C. 0.11
D. 0.12
The researcher must decide on the level of significance before formulating a decision
rule and collecting sample data.
A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces.
Then, once the machine is running, a sample of six tubes is taken every three hours and
weighed with the following results:
What is the range of the samples at 7 am?
A. 0.05
B. 0.06
C. 0.11
D. 0.12
The range of possible values for the Durbin-Watson statistic is:
A. any value.
B. any value greater than zero.
C. any value from zero to four inclusive.
D. any value less than zero.
A sample of 50 is selected from a known population of 250 elements. The population
standard deviation is 15. Using the finite correction factor, what is the standard error of
the sample means?
A. 2.89
B. 1.90
C. 2.12
D. Cannot be determined
Refer to the following breakdown of responses to a survey of room service in a hotel.
What is the class interval for the frequency table above?
A. 10
B. 20
C. 40
D. None Apply
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. â…› or 0.125
D. 1/495 or 0.002
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:
Why is the table NOT a frequency distribution?
A. The number of males does not equal the sum of males that smoke and do not smoke.
B. The classes are not mutually exclusive.
C. There are too many classes.
D. Class limits cannot be computed.
A random sample of 400 families who planned to buy a vacation residence revealed that
228 families want to buy a condominium in Florida. What is the test statistic to evaluate
the statement that 55% of those families who plan to purchase a vacation residence in
Florida want a condominium?
On a very hot summer day, 5% of the production employees at Midland States Steel are
absent from work. The production employees are randomly selected for a special
in-depth study on absenteeism. What is the probability of randomly selecting 10
production employees on a hot summer day and finding that none of them are absent?
A. 0.002
B. 0.344
C. 0.599
D. 0.100
The _____________________ is the difference between the expected monetary value
under conditions of certainty and the expected monetary value under uncertainty.
The relationship between interest rates as a percent (X) and housing starts (Y) is given
by the linear equation Ŷ = 4094 – 269X. For what interest rate will the maximum
number of housing starts be achieved?
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?
You have a decision to invest $10,000 in any of four different companies. You estimate
the probabilities that the economy will be favorable or unfavorable, and you estimate
the percent returns over the next year.
What is the maximin choice?
Six people have declared their intentions to run for a seat on the school board in the
next local election. A poll is conducted during the campaign among 1,020 randomly
sampled voters to determine if there is any clear preference among the voters. The
responses are shown next.
What is the computed chi-square statistic?
The waiting time for patients at a local walk-in health clinic follows a normal
distribution with a mean of 15 minutes and a population standard deviation of 5
minutes. The clinic wants to know if the waiting time is less than 15 minutes. The
quality-assurance department sampled 50 patients and found that the mean waiting time
was 14.25 minutes. For a significance level of 0.05, what is the critical value?
If π = 1/5 and n = 100, the standard deviation of this binomial distribution is _____.
The distribution of annual salaries for 52 employees in a small manufacturing company
has the following averages: the mean is $25,459, the median is $24,798 and the mode is
$24,000. What is the total amount paid for employee salaries?
A company compared the variance of salaries for employees who have been employed
for 5 years or less with employees who have been employed for 10 years or more. They
randomly selected 21 employees with 5 years or less experience and 15 employees with
10 years or more experience. The standard deviation for the group with 5 years or less
experience was $2,225; the standard deviation for the group with 10 years or more
experience was $1,875. What is the F test statistic for the hypothesis test?
To apply the normal approximation to a binomial distribution, mean, and variance are
________.