Probability Concepts and Applications test bank

2.91 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

2.92 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

2.93 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

2.94 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

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2.95 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

2.96 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

2.97 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

2.98 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) 0.9452
(e) none of the above

2.99 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

2.100 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

2.101 The time required to travel downtown at 10am 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

2.102 The time required to travel downtown at 10am 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

2.103 The time required to travel downtown at 10am 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

2.104 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

2.105 The number of cars passing through an intersection in the next five minutes can usually be described by the

(a) normal distribution.

(b) uniform distribution.

(c) exponential distribution.

(d) Poisson distribution.

(e) none of the above

ANSWER: d {moderate, THE POISSON DISTRIBUTION}

2.106 Arrivals at a fast-food restaurant follow a Poisson distribution with a mean arrival rate of 16
customers per hour. What is the probability that in the next hour there will be exactly 12 arrivals?

(a) 0.0000

(b) 0.0661

(c) 0.7500

(d) 0.1322

(e) none of the above

2.107 Arrivals at a fast-food restaurant follow a Poisson distribution with a mean arrival rate of 16 customers per hour. What is the probability that in the next hour there will be exactly 8 arrivals?

(a) 1.000

(b) 0.200

(c) 0.175

(d) 0.825

(e) none of the above

2.108 Which of the following characteristics is not true for the exponential distribution?

(a) It is discrete probability distribution.

(b) It is also called the negative exponential distribution.

(c) It is used in dealing with queuing problems.

(d) It is used to describe the times between customer arrivals.

(e) The variance is the square of the expected value.

2.109 The length of time that it takes the tollbooth attendant to service each driver can typically be described by the

(a) normal distribution.

(b) uniform distribution.

(c) exponential distribution.

(d) Poisson distribution.

(e) none of the above