Chapter 2 Probability Concepts and Applications

91) Historical data indicates that only 20% of cable customers are willing to switch companies. If a binomial process is assumed, then in a sample of 20 cable customers, what is the probability that exactly 2 customers would be willing to switch their cable?

A) 0.1

B) 0.04

C) 0.137

D) 0.206

E) 0.794

92) Historical data indicates that only 20% of cable customers are willing to switch companies. If a binomial process is assumed, then in a sample of 20 cable customers, what is the probability that no more than 3 customers would be willing to switch their cable?

A) 0.85

B) 0.15

C) 0.20

D) 0.411

E) 0.589

93) Historical data indicates that only 20% of cable customers are willing to switch companies. If a binomial process is assumed, then in a sample of 20 cable customers, what is the probability that between 2 and 5 (inclusive) customers are willing to switch companies?

A) 0.1369

B) 0.1746

C) 0.0377

D) 0.7350

E) 0.500

94) Properties of the normal distribution include

A) a continuous bell-shaped distribution.

B) a discrete probability distribution.

C) the number of trials is known and is either 1, 2, 3, 4, 5, etc.

D) the random variable can assume only a finite or limited set of values.

E) use in queuing.

95) Which of the following characteristics is true for a normal probability distribution?

A) The area under the curve is 1.

B) It is symmetrical.

C) The midpoint is also the mean.

D) Sixty-eight percent of the area under the curve lies within ± one standard deviation of the mean.

E) All of the above are true.

96) The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses fewer than 600 minutes?

A) 0

B) 0.023

C) 0.841

D) 0.977

E) None of the above

97) The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses fewer than 400 minutes?

A) 0

B) 0.023

C) 0.159

D) 0.977

E) None of the above

98) The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses more than 350 minutes?

A) 0.001

B) 0.999

C) 0.618

D) 0.382

E) None of the above

99) The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses more than 580 minutes?

A) 0.152

B) 0.0548

C) 0.848

D) 0.903

E) None of the above

Skills

100) The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses between 400 and 500 minutes?

A) 0.4773

B) 0.05228

C) 0.0228

D) 0.9773

E) None of the above

101) Data for a particular subdivision near downtown Houston indicate that the average price per square foot for a home is $100 with a standard deviation of $5 (normally distributed). What is the probability that the average price per square foot for a home is greater than $110?

A) 0

B) 0.023

C) 0.841

D) 0.977

E) None of the above

102) Data for a particular subdivision near downtown Houston indicate that the average price per square foot for a home is $100 with a standard deviation of $5 (normally distributed). What is the probability that the average price per square foot for a home is greater than $90?

A) 0

B) 0.023

C) 0.159

D) 0.977

E) None of the above

103) Data for a particular subdivision near downtown Houston indicate that the average price per square foot for a home is $100 with a standard deviation of $5 (normally distributed). What is the probability that the average price per square foot for a home is less than $85?

A) 0.001

B) 0.999

C) 0.618

D) 0.382

E) None of the above

104) Data for a particular subdivision near downtown Houston indicate that the average price per square foot for a home is $100 with a standard deviation of $5 (normally distributed). What is the probability that the average price per square foot for a home is less than $108?

A) 0.152

B) 0.097

C) 0.848

D) 0.945

E) None of the above

105) The time required to complete a project is normally distributed with a mean of 80 weeks and a standard deviation of 10 weeks. The construction company must pay a penalty if the project is not finished by the due date in the contract. If a construction company bidding on this contract puts in a due date of 80 weeks, what is the probability that they will have to pay a penalty?

A) 0

B) 1.000

C) 0.500

D) 1/8

E) None of the above

106) The time required to complete a project is normally distributed with a mean of 80 weeks and a standard deviation of 10 weeks. The construction company must pay a penalty if the project is not finished by the due date in the contract. If a construction company bidding on this contract wishes to be 90 percent sure of finishing by the due date, what due date (project week #) should be negotiated?

A) 81.28

B) 92.8

C) 81.82

D) .81954

E) None of the above

107) The time required to travel downtown at 10 a.m. on Monday morning is known to be normally distributed with a mean of 40 minutes and a standard deviation of 5 minutes. What is the probability that it will take less than 40 minutes?

A) 0.50

B) 0.20

C) 0.80

D) 1.00

E) None of the above

108) The time required to travel downtown at 10 a.m. on Monday morning is known to be normally distributed with a mean of 40 minutes and a standard deviation of 5 minutes. What is the probability that it will take less than 35 minutes?

A) 0.84134

B) 0.15866

C) 0.53983

D) 0.46017

E) None of the above

109) The time required to travel downtown at 10 a.m. on Monday morning is known to be normally distributed with a mean of 40 minutes and a standard deviation of 5 minutes. What is the probability that it will take more than 40 minutes?

A) 0.2500

B) 0.0625

C) 1.000

D) 0.5000

E) None of the above

110) Queuing Theory makes use of the

A) normal probability distribution.

B) uniform probability distribution.

C) binomial probability distribution.

D) Poisson probability distribution.

E) None of the above