Chapter 5

Question 1

Variables that take on values at every point over a given interval are called _______________ _______________ variables.

Answer 1

Continuous Random

Question 2

If the set of all possible values of a variable is at most finite or a countably infinite number of possible values, then the variable is called a _______________ _______________ variable.

Answer 2

Discrete Random

Question 3

An experiment in which a die is rolled six times will likely produce values of a _______________ random variable.

Answer 3

Discrete

Question 4

An experiment in which a researcher counts the number of customers arriving at a
supermarket checkout counter every two minutes produces values of a _______________
random variable.

Answer 4

Discrete

Question 5

An experiment in which the time it takes to assemble a product is measured is likely to produce values of a _______________ random variable.

Answer 5

Continuous

Question 6

A binomial distribution is an example of a _______________ distribution.

Answer 6

Discrete

Question 7

The normal distribution is an example of a _______________ distribution.

Answer 7

Continuous

Question 8

The long-run average of a discrete distribution is called the __________________ or
______________________________________.

Answer 8

Mean, Expected Value

Question 9

Use the following discrete distribution to answer 9 and 10. The mean of the discrete distribution is
x P(x)
1 .435
2 .241 3 .216
4 .108

Answer 9

1.997

Question 10

Use the following discrete distribution to answer 9 and 10. The variance of the discrete distribution above is
x P(x)
1 .435
2 .241 3 .216
4 .108

Answer 10

1.083

Question 11

On any one trial of a binomial experiment, there can be only _______________ possible
outcomes.

Answer 11

Two

Question 12

Suppose the probability that a given part is defective is .10. If four such parts are randomly
drawn from a large population, the probability that exactly two parts are defective is
________.

Answer 12

0.0486

Question 13

Suppose the probability that a given part is defective is .04. If thirteen such parts are randomly drawn from a large population, the expected value or mean of the binomial distribution that describes this experiment is ________.

Answer 13

0.52

Question 14

Suppose a binomial experiment is conducted by randomly selecting 20 items where p = .30. The standard deviation of the binomial distribution is _______________.

Answer 14

2.049

Question 15

Suppose forty-seven percent of the workers in a large corporation are under thirty-five years of age. If fifteen workers are randomly selected from this corporation, the probability of selecting exactly ten who are under thirty-five years of age is _______________.

Answer 15

.0661

Question 16

Suppose that twenty-three percent of all adult Americans fly at least once a year. If twelve adult Americans are randomly selected, the probability that exactly four have flown at least once last year is _______________.

Answer 16

.1712

Question 17

Suppose that sixty percent of all voters support the President of the United States at this time. If twenty voters are randomly selected, the probability that at least eleven support the President is _______________.

Answer 17

.755

Question 18

The Poisson distribution was named after the French mathematician _______________.

Answer 18

Poisson

Question 19

The Poisson distribution focuses on the number of discrete occurrences per _______________.

Answer 19

Interval

Question 20

The Poisson distribution tends to describe _______________ occurrences.

Answer 20

Rare

Question 21

The long-run average or mean of a Poisson distribution is _______________.

Answer 21

Lambda

Question 22

The variance of a Poisson distribution is equal to _______________.

Answer 22

Lambda

Question 23

If Lambda is 2.6 occurrences over an interval of five minutes, the probability of getting six occurrences over one five minute interval is _______________.

Answer 23

0.0319

Question 24

Suppose that in the long-run a company determines that there are 1.2 flaws per every twenty pages of typing paper produced. If ten pages of typing paper are randomly selected, the probability that more than two flaws are found is _______________.

Answer 24

.0232

Question 25

If Lambda is 1.8 for a four minute interval, an adjusted new Lambda of _______ would be used to analyze the number of occurrences for a twelve minute interval.5.4

Answer 25

5.4

Question 26

Suppose a binomial distribution problem has an n = 200 and a p = .03. If this problem is worked using the Poisson distribution, the value of Lambda is ________.

Answer 26

6.0

Question 27

The hypergeometric distribution should be used when a binomial type experiment is being conducted without replacement and the sample size is greater than or equal to ________% of the population.

Answer 27

5

Question 28

Suppose a population contains sixteen items of which seven are X and nine are Y. If a random sample of five of these population items is selected, the probability that exactly three of the five are X is ________.

Answer 28

0.2885

Question 29

Suppose a population contains twenty people of which eight are members of the Catholic church. If a sample of four of the population is taken, the probability that at least three of the four are members of the Catholic church is ________.

Answer 29

0.1531

Question 30

Suppose a lot of fifteen personal computer printers contains two defective printers. If three of the fifteen printers are randomly selected for testing, the probability that no defective printers are selected is _______________.

Answer 30

0.6286