A discrete variable may assume fractional or decimal values, but they must have distance
between them.
Answer: True
9. For a binomial distribution, each trial has a known number of successes. For example, a
four question multiple-choice test can only have

A binomial distribution has a characteristic that the trials are independent, which means that
the outcome of one trial does not affect the outcome of any other trial.
Answer: True
16. For a binomial distribution, outcomes of an experiment are classified

The production department has installed a new spray machine to paint automobile doors. As
is common with most spray guns, unsightly blemishes often appear because of improper
mixture or other problems. A worker counted the number of blemishes on each door

If the variance of a probability was computed to be 3.6 grams, what is the standard deviation?
A) 0.6
B) 1.9
C) 6.0
D) 12.96
Answer: B
39. Sixty percent of the customers of a fast food chain order the Whopper, french
fries and a drink. If a random sample

The probability of a particular outcome, designated X, must always be between 0 and 100
inclusive.
Answer: False
5. If we toss two coins and count the number of heads, there could be 0, 1 or 2 heads. Since
the exact number of heads resulting from this exp

On a very hot summer day, 5 percent 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 prod

A _ random variable can assume only a certain number of separated values.
Answer: discrete
85. A continuous random variable can assume one of an _ number of
values within a specific range.
Answer: infinite
Difficulty: Medium
Goal: 2
86. In the _ distribut

A new car was put into production. It involved many assembly tasks. Each car was
inspected at the end of the assembly line and the number of defects per unit was recorded.
For the first 100 cars produced, there were 40 defective cars. Some of the cars had

Which one of the following is NOT a condition of the binomial distribution?
A) Independent trials
B) Only two outcomes
C) Probability of success remains constant from trial to trial
D) At least 10 observations
Answer: D
50. Which is true for a binomial di

A farmer who grows genetically engineered corn is experiencing trouble with corn borers. A
random check of 5,000 ears revealed the following: many of the ears contained no borers.
Some ears had one borer; a few had two borers; and so on. The distribution

A binomial distribution is a continuous probability distribution.
Answer: False
24. The binomial and Poisson distributions are discrete probability distributions.
Answer: True
Difficulty: Easy
Goal: 4, 6
25. To construct a binomial distribution, it is nec

The probabilities and the number of automobiles lined up at a Lakeside Olds at opening time
(7:30 a.m.) for service are:
On a typical day, how many automobiles should Lakeside Olds expect to be lined up at
opening?
A) 10.00
B) 1.00
C) 2.85
D) 1.96
Answer:

Sweetwater & Associates write weekend trip insurance at a very nominal charge. Records
show that the probability that a motorist will have an accident during the weekend and file a
claim is 0.0005. Suppose they wrote 400 policies for the coming weekend, w

Which shape describes a Poisson distribution?
A) Positively skewed
B) Negatively skewed
C) Symmetrical
D) All of the above
Answer: A
52. Sponsors of a local charity decided to attract wealthy patrons to its $500-a-plate
dinner by allowing each patron to b

What must you know to develop a binomial probability distribution?
A) Probability of success
B) Number of trials
C) Number of successes
D) "a" and "b" only
E) "a" and "c" only
Answer: D
70. In a Poisson distribution the mean is equal to
A) n
B)
C) e - x.

Carlson Jewelers permits the return of their diamond wedding rings, provided the return
occurs within two weeks of the purchase date. Their records reveal that 10 percent of the
diamond wedding rings are returned. Five different customers buy five rings.

A random variable with a Poisson distribution has one of _ mutually exclusive values.
Answer: two
89. In a Poisson distribution each trial is _.
Answer: independent
Difficulty: Medium
Goal: 6
90. The arrival of customers at a service desk follows a Poisso

Judging from recent experience, 5 percent of the computer keyboards produced by an
automatic, high-speed machine are defective. What is the probability that out of six
keyboards selected at random, exactly zero keyboards will be defective?
A) 0.001
B) 0.1

A random variable represents the outcomes of an experiment.
Answer: True
4. The probability of a particular outcome, designated X, must always be between 0 and 100
inclusive.
Answer: False
Difficulty: Easy
Goal: 1
5. If we toss two coins and count the num

A true-false test consists of six questions. If you guess the answer to each question, what is
the probability of getting all six questions correct?
A) 0
B) 0.016
C) 0.062
D) 0.250
Answer: B
63. A farmer who grows genetically engineered corn is experienci

Which of the following is NOT a characteristic of a binomial probability distribution?
A) Each outcome is mutually exclusive
B) Each trial is independent
C) Probability of success remains constant from trial to trial
D) Each outcome results from two trial

In which of the following discrete distribution does the probability of a success vary from one
trial to the next?
A) Binomial
B) Poisson
C) Hypergeometric
D) All of the above
Answer: C
47. Which of the following is a requirement for use of the hypergeome

What is a listing of all possible outcomes of an experiment and their corresponding
probability of occurrence called?
A) Random variable
B) Probability distribution
C) Subjective probability
D) Frequency distribution
Answer: B
49.
Which one of the followi

The random variable for a Poisson probability distribution can assume an infinite number of
values.
Answer: True
11. A probability distribution is a mutually exclusive listing of experimental outcomes that
can occur by chance and their corresponding proba

29. The variance of a binomial distribution is found by
(1 - ).
Answer: True
30. As a general rule of thumb, if the items selected for a sample are not replaced and the
sample size is less than 5 percent of the population, the binomial distribution can be

The Poisson probability distribution is a continuous probability distribution.
Answer: False
14. If we measure the weight of a car, the variable is a discrete random variable.
Answer: False
Difficulty: Easy
Goal: 2
15. A binomial distribution has a charac

The variance of the sum of two random variables is the sum of their variances plus two times
the covariance.
Answer: True
37. If the covariance between two random variables is zero, the two variables are not related.
Answer: True
Multiple Choice
Difficult

This is an example of what type of probability distribution? _
Answer: hypergeometric
Multiple Choice
Use the following to answer questions 104-106:
A statistics professor receives an average of five e-mail messages per day from students.
Assume the numbe

This situation is an example of what type of discrete probability distribution?
_
Answer: binomial probability distribution
Multiple Choice Questions
Use the following to answer questions 96-99:
David's gasoline station offers 4 cents off per gallon if th

What is the probability that no woman is selected?
A) 1/5
B) 1/3
C) 2/15
D) 8/15
Answer: B
101. What is the probability that at least one woman is selected?
A) 8/15
B) 3/5
C) 2/3
D) 3/4
Answer: C
Difficulty: Hard
Goal: 5
Fill-in-the-Blank
102. What is the