There are 10 AAA batteries in a box and 3 are defective. Two batteries are selected
without replacement. What is the probability of selecting a defective battery followed
by another defective battery?
A. or 0.50
B. or 0.25
C. 1/120 or about 0.0083
D. 1/15 or about 0.07
For an annual time series extending from 2000 through 2010, how many years would be
lost in a three-year moving average?
A. Two at the start and one at the end
B. One at the start and one at the end
C. Two at the start and zero at the end
D. Zero at the start and two at the end
A sample of 100 production workers is obtained. The workers are classified by gender
(male, female) and by age (under 20, 20-29, 30-39, and 40 or over). How many degrees
of freedom are there?
A. 0
B. 3
C. 6
D. 5
An experiment consists of making 80 telephone calls in order to sell a particular
insurance policy. The random variable in this experiment is a ___________.
A. discrete random variable
B. continuous random variable
C. complex random variable
D. simplex random variable
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.
How many degrees of freedom are there?
A. 2
B. 3
C. 4
D. 5
In a management trainee program, 80% of the trainees are female, while 20% are male.
Ninety percent of the females attended college; 78% of the males attended college. A
management trainee is selected at random. What is the probability that the person
selected is a male who did NOT attend college?
A. P (male) P (did not attend college | male)
B. P (did not attend college) P (male | did not attend college)
C. P (male) P (did not attend college)
D. P (did not attend college)
Customers of the Key Refining Company charge an average of $70 per month. The
distribution of amounts charged is approximately normal, with a standard deviation of
$10. What is the probability of selecting a credit card customer at random and finding
the customer charged between $70 and $83?
A. 0.1962
B. 0.4032
C. 0.3413
D. 0.4750
The number of trials and the population proportion are respectively represented by what
symbols?
A. p and n
B. α and β
C. z and t
D. n and π
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
When comparing the 95% confidence and prediction intervals for a given regression
analysis ______________.
A. The confidence interval is wider than a prediction interval
B. The confidence interval is narrower than a prediction interval
C. There is no difference between confidence and prediction intervals
D. The prediction interval has a higher level of confidence
Which value of r indicates a stronger correlation than 0.40?
A. -0.30
B. -0.80
C. +0.38
D. 0
If we reject the null hypothesis, H0: , what can we conclude about the
population correlation coefficient?
A. It is zero.
B. It could be zero.
C. It is not zero.
D. It equals the computed sample correlation.
Which of the following can be used to test the hypothesis that two nominal variables are
related?
A. A contingency table analysis
B. A goodness-of-fit
C. ANOVA
D. A regression analysis
Accounting procedures allow a business to evaluate their inventory costs based on two
methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer
evaluated its finished goods inventory (in $000s) for five products with the LIFO and
FIFO methods. To analyze the difference, they computed (FIFO – LIFO) for each
product. Based on the following results, does the LIFO method result in a lower cost of
inventory than the FIFO method?
What are the degrees of freedom?
A. 4
B. 5
C. 15
D. 10
Variation describes the degree of dispersion in the data.
The following table classifies 100 individuals using two variables, gender and college
attended.
What is this two-way classification called?
A. Goodness-of-fit test
B. Frequency table
C. ANOVA table
D. Contingency table
Mileage tests were conducted on a randomly selected sample of 100 newly developed
automobile tires. The results showed that the mean tread life was 50,000 miles, with a
standard deviation of 3,500 miles. What is the best estimate of the mean tread life in
miles for the entire population of these tires?
A. 50,000
B. 3,500
C. 500
D. 35
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
In the Kruskal-Wallis method, testing for differences among populations is based on the
sum of the ________.
Even if it is zero, every time series has a ________ component.
When the data is divided by the seasonal indexes, the ____________ is removed from a
time series.
_____ is the symbol used to designate a base period price.
Explain the risks of acceptance sampling.