THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING:

The probability that a person catches a cold during the cold and flu season is 0.4. Assume that 10 people are chosen at random.

128) What is the probability that exactly four of them will catch a cold?

A) 0.7502

B) 0.6330

C) 0.3670

D) 0.2508

129) What is the probability that four or more of them will catch a cold?

A) 0.715

B) 0.618

C) 0.546

D) 0.312

130) On average, how many of these ten people would you expect to catch a cold?

A) 4

B) 3

C) 2

D) 1

131) What is the standard deviation for the number of people catching a cold?

A) 1.549

B) 1.245

C) 1.265

D) 1.125

132) Which of the following can be used to approximate the binomial distribution when the number of trialsnis large and the probability of successPis small such thatnP 7?

A) Poisson distribution

B) hypergeometric distribution

C) any discrete distribution

D) any distribution with a mean equals 7

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING:

On average, you receive 2.6 pieces of junk mail a day. Assume that the number of pieces of junk mail you receive each day follows the Poisson distribution.

133) What is the probability that you receive exactly three pieces of junk mail today?

A) 0.198

B) 0.233

C) 0.218

D) 0.176

134) What is the probability of receiving more than three pieces of junk mail today?

A) 0.123

B) 0.264

C) 0.482

D) 0.242

135) What is the standard deviation of the number of pieces of junk mail you receive daily?

A) 1.61

B) 2.60

C) 6.76

D) There is not sufficient information to determine this.

136) What is the expected number of pieces of junk mail you receive daily?

A) 6.76

B) 1.61

C) 3.22

D) 2.60

137) Consider the following probability distribution. Which of the following is true?

x

0

1

2

3

4

5

6

7

P(x)

0.05

0.16

0.19

0.24

0.18

0.11

0.05

0.02

A)P(2 <X< 5) = 0.42

B)P(X> 6) = 0.07

C)P(X 3) = 0.64

D)P(X 6) = 0.93

138) If the outcomes of a discrete random variable follow a Poisson distribution, then their:

A) mean equals the standard deviation.

B) mean equals the variance.

C) median equals the variance.

D) median equals the standard deviation.

139) Which of the following is an example of a discrete random variable?

A) The distance you can drive in a car with a full tank of gas.

B) The number of cows on a cattle ranch.

C) The weight of a package at the post office.

D) The amount of rain that falls over a 24-hour period.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING:

A company hires management trainees for entry level sales positions. Past experience indicates that only 10% will still be employed at the end of nine months. Assume the company recently hired six trainees.

140) What is the probability that three of the trainees will still be employed at the end of nine months?

A) 0.0012

B) 0.0146

C) 0.0415

D) 0.0446

141) What is the probability that at least two of the trainees will still be employed at the end of nine months?

A) 0.9841

B) 0.0984

C) 0.1143

D) 0.0159

142) What is the probability that none of the trainees will still be employed at the end of nine months?

A) 0.5314

B) 0.3771

C) 0.4686

D) 0.0000

143) What is the probability that between one and three (inclusive) of the trainees will still be employed at the end of nine months?

A) 0.3543

B) 0.0984

C) 0.0146

D) 0.4673

144) What is the expected number of the trainees that will still be employed at the end of nine months?

A) 0.6

B) 0.9

C) 3.0

D) 4.0

145) What is the standard deviation of the number of trainees that will still be employed at the end of nine months?

A) 0.540

B) 0.240

C) 0.735

D) 0.490

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING:

On average, there are 3.2 defects in a sheet of rolled steel. Assume that the number of defects follows a Poisson distribution.

146) What is the probability of having exactly three defects in a roll?

A) 0.412

B) 0.223

C) 0.318

D) 0.335

147) What is the probability of having more than three defects in a roll?

A) 0.354

B) 0.398

C) 0.412

D) 0.621

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING:

A basketball player makes 80 percent of his free throws during the regular season. Consider his next eight free throws.

148) What is the probability that he will make exactly six free throws?

A) 0.1468

B) 0.3355

C) 0.1678

D) 0.2936

149) What is the probability that he will make at least six free throws?

A) 0.1468

B) 0.3355

C) 0.7969

D) 0.2936

150) What is the probability that he will make between four and six (inclusive) free throws?

A) 0.1468

B) 0.4863

C) 0.4404

D) 0.6291

151) What is the expected number of free throws that he will make?

A) 6.4

B) 6.0

C) 5.0

D) 4.0

152) What is the standard deviation of the number of free throws that he will make?

A) 1.131

B) 1.280

C) 2.608

D) 2.828

153) The finishing process on new furniture leaves slight blemishes. The table below displays a manager's probability assessment of the number of blemishes in the finish of new furniture.

Number of Blemishes

0

1

2

3

4

5

Probability

0.34

0.25

0.19

0.11

0.07

0.04

On average, how many defects would we expect on a piece of furniture?

A) 0.28

B) 0.85

C) 1.44

D) 0.77

154) Thirty percent of all households have a DVD player. If you select 20 houses at random, what is the probability that six or fewer of them have a DVD player?

A) 0.608

B) 0.416

C) 0.344

D) 0.238

155) The number of rainy days per month at Seattle follows a Poisson distribution with a mean value of 4.5 days. What is the probability that it will rain 3 days next month?

A) 0.3604

B) 0.2222

C) 0.1687

D) 0.2521