Deck 6: Addiction and Drug Abuse

Question 1

Which of the following statements is true regarding z-scores for the normal probability distribution?

A)z-scores are equal to 1.0 for values of x that are equal to the distribution mean.
B)z-scores are zero for values of x that are less than the distribution mean.
C)z-scores are positive for values of x that are less than the distribution mean.
D)z-scores are negative for values of x that are less than the distribution mean.

Answer 1

z-scores are negative for values of x that are less than the distribution mean.

Question 2

Assume that the average talk time on an Apple iPhone is 20 hours and that this time follows the exponential probability distribution. What is the probability that a randomly selected iPhone will experience more than 23 hours of talk time?

A)0.1969
B)0.5916
C)0.4258
D)0.3166

Answer 2

0.3166

Question 3

The time that customers wait to be served at the delicatessen for a grocery store follows the uniform distribution between 0 and 7 minutes. What is the probability that a randomly selected customer will wait less than 2 minutes at the deli?

A)0.1429
B)0.5714
C)0.8571
D)0.2857

Answer 3

0.2857

Question 4

During the 3 PM to 5 PM time period, cars arrive at a bank's drive-through window at an average rate of 15 customers per hour. Assume that the time between arrivals follows the exponential distribution. What is the probability that a randomly selected customer will arrive more than 10 minutes after the previous customer?

A)0.3670
B)0.1515
C)0.2732
D)0.0821

Question 5

Costco installs automobile tires on a first-come first-serve basis. The total time a customer needs to wait for the installation to be completed follows the normal distribution with a mean time of 106.3 minutes and a standard deviation of 18.5 minutes. What is the probability that a randomly selected customer will wait less than 100 minutes for his or her tires to be installed?

A)0.3669
B)0.2578
C)0.4761
D)0.1151

Question 6

Assume that the flight time for U.S. Airways flight 1267 from Philadelphia to Dallas follows the uniform probability distribution between 210 and 250 minutes. What is the probability that a randomly selected flight will take less than 224 minutes?

A)0.60
B)0.35
C)0.18
D)0.46

Question 7

Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. What is the probability that a randomly selected airfare between these two cities will be more than $450?

A)0.2033
B)0.3669
C)0.0788
D)0.1788

Question 8

According to Bureau of Labor Statistics, 26.0% of the total part- time workforce in the U.S. was between the ages of 25 and 34 during a recent month. A random sample of 90 part- time employees was selected during this quarter. Using the normal approximation to the binomial distribution, what is the probability that more than 27 people from this sample were between the ages of 25 and 34?

A)0.3034
B)0.1611
C)0.1025
D)0.0668

Question 9

Bob's golf score at his local course follows the normal distribution with a mean of 92.1 and a standard deviation of 3.8. What is the probability that the score on his next round of golf will be between 82 and 89?

A)0.3960
B)0.4832
C)0.3269
D)0.2022

Question 10

A survey conducted in 2011 asked employed adults from age 25 to 70 if they plan to keep a foot in the working world after retirement. Thirty-three percent of the respondents answered "very likely". A random sample of 75 adults from this age group was asked the same question. Using the normal approximation to the binomial distribution, what is the probability that 20, 21, 22, or 23 adults from this sample would very likely plan to keep a foot in the working world after retirement?

A)0.4560
B)0.6539
C)0.1510
D)0.3821

Question 11

During the 2013 Major League Baseball season, the St. Louis Cardinals averaged 41,602 fans per home game. Suppose attendance during the season follows the normal probability distribution with a standard deviation of 9,440 per game. The interval around the mean that contains 95% of the attendance is ________ .

A)18,002, 65,202
B)22,722, 60,482
C)3,842, 79,362
D)13,282, 69,922

Question 12

Costco installs automobile tires on a first-come first-serve basis. The total time a customer needs to wait for the installation to be completed follows the normal distribution with a mean time of 106.3 minutes and a standard deviation of 18.5 minutes. The interval around the mean that contains 68% of the wait time for customers is -----.

A)69.3, 143.3
B)50.8, 161.8
C)87.8, 124.8
D)32.3, 180.3

Question 13

Suppose the average tread-life of a certain brand of tire is 42,000 miles and that this mileage follows the exponential probability distribution. What is the probability that a randomly selected tire will have a tread-life of less than 65,000 miles?

A)0.4497
B)0.7872
C)0.3084
D)0.5630

Question 14

The time that customers wait to be served at the delicatessen for a grocery store follows the uniform distribution between 0 and 7 minutes. What is the standard deviation of this distribution?

A)2.02
B)3.65
C)4.10
D)1.16

Question 15

Assume that the amount of time that it takes an employee to service a car at an oil change facility follows the uniform probability distribution between 21 and 38 minutes. What is the probability that a randomly selected car will require less than 25 minutes to service?

A)0.5716
B)0.2353
C)0.4860
D)0.3146

Question 16

Costco installs automobile tires on a first-come first-serve basis. The total time a customer needs to wait for the installation to be completed follows the normal distribution with a mean time of 106.3 minutes and a standard deviation of 18.5 minutes. What is the probability that a randomly selected customer will wait between 80 and 95 minutes for his or her tires to be installed?

A)0.1245
B)0.2960
C)0.3455
D)0.1931

Question 17

Bananas are sold in bunches at a grocery store and typically consist of 4-8 bananas per bunch. Suppose the weight of these bunches follows a normal distribution with a mean of 3.54 pounds and a standard deviation of 0.63 pounds. What is the probability that a randomly selected bunch of bananas will weigh between 3.6 and 4.2 pounds?

A)0.4641
B)0.2676
C)0.4090
D)0.3133

Question 18

Suppose the average tread-life of a certain brand of tire is 42,000 miles and that this mileage follows the exponential probability distribution. What is the probability that a randomly selected tire will have a tread-life of more than 40,000 miles?

A)0.3858
B)0.3016
C)0.1546
D)0.2410

Question 19

According to the MIT Airline Data Project, American Airlines controlled 15.5% of the domestic market during a recent year. A random sample of 125 domestic passengers that year was selected. Using the normal approximation to the binomial distribution, what is the probability that 20, 21, 22, 23, 24, or 25 passengers from this sample were on American Airline flights?

A)0.4225
B)0.6810
C)0.5319
D)0.2534

Question 20

The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. The interval around the mean that contains 68% of the times needed to grade exams is------ .

A)5.8, 26.8
B)7.9, 24.7
C)3.7, 28.9
D)12.1, 20.5

Question 21

Costco installs automobile tires on a first-come first-serve basis. The total time a customer needs to wait for the installation to be completed follows the normal distribution with a mean time of 106.3 minutes and a standard deviation of 18.5 minutes. What is the probability that a randomly selected customer will wait more than 125 minutes for his or her tires to be installed?

A)0.2090
B)0.1562
C)0.3409
D)0.4920

Question 22

John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. The interval around the mean that contains 99.7% of the commute times is -------.

A)6.3, 47.1
B)21.6, 31.8
C)16.5, 36.9
D)11.4, 42.0

Question 23

Assume that the flight time for U.S. Airways flight 1267 from Philadelphia to Dallas follows the uniform probability distribution between 210 and 250 minutes. What is the probability that a randomly selected flight will take between 220 and 235 minutes?

A)0.557
B)0.633
C)0.375
D)0.480

Question 24

Which of the following probability distribution is not continuous?

A)normal
B)Poisson
C)exponential
D)All of these are continuous probability distributions.

Question 25

Which of the following experiments does not generate a continuous random variable?

A)recording the number of miles traveled between two locations
B)measuring the number of ounces of soda in a bottle
C)counting the number of customers who enter a store during the business day
D)recording the number of minutes a customer waits on hold for technical support

Question 26

Bananas are sold in bunches at a grocery store and typically consist of 4-8 bananas per bunch. Suppose the weight of these bunches follows a normal distribution with a mean of 3.54 pounds and a standard deviation of 0.63 pounds. What is the probability that a randomly selected bunch of bananas will weigh more than 3.0 pounds?

A)0.9463
B)0.8051
C)0.6950
D)0.5398

Question 27

Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. What is the probability that a randomly selected airfare between these two cities will be less than $300?

A)0.3192
B)0.1020
C)0.2005
D)0.4286

Question 28

A smaller standard deviation for the normal probability distribution results in

A)a skinnier curve that is tighter and taller around the mean.
B)a fatter curve that is tighter and taller around the mean.
C)a fatter curve that is more spread out around the mean and not as tall.
D)a skinnier curve that is more spread out around the mean and not as tall.

Question 29

According to the Bureau of Labor Statistics, 7.1% of the labor force was recently unemployed. A random sample of 100 employable adults was selected. Using the normal approximation to the binomial distribution, what is the probability that 6 or more people from this sample are unemployed?

A)0.4030
B)0.7324
C)0.3219
D)0.5561

Question 30

Which of the following statements is true regarding the normal probability distribution?

A)The mean is always greater than the median.
B)The mean is always less than the median.
C)The mean is always greater than the mode.
D)The mean and median are roughly equal to one another.

Question 31

The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. What is the probability that a randomly selected exam will require less than 20 minutes to grade?

A)0.3715
B)0.9230
C)0.8106
D)0.6328

Question 32

During the 3 PM to 5 PM time period, cars arrive at a bank's drive-through window at an average rate of 15 customers per hour. Assume that the time between arrivals follows the exponential distribution. What is the probability that a randomly selected customer will arrive between 2 and 6 minutes after the previous customer?

A)0.3834
B)0.1776
C)0.2395
D)0.0560

Question 33

John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. What is the probability that the commute time for a randomly selected day will be less than 18 minutes?

A)0.0436
B)0.0778
C)0.2236
D)0.1271

Question 34

The ---- probability distribution is bell-shaped and symmetrical.

A)normal
B)uniform
C)Poisson
D)exponential

Question 35

Bob's golf score at his local course follows the normal distribution with a mean of 92.1 and a standard deviation of 3.8. What is the probability that the score on his next round of golf will be less than 100?

A)0.8665
B)0.7357
C)0.9812
D)0.5000

Question 36

During the 2013 Major League Baseball season, the St. Louis Cardinals averaged 41,602 fans per home game. Suppose attendance during the season follows the normal probability distribution with a standard deviation of 9,440 per game. What is the probability that a randomly selected game during the 2013 season had an attendance greater than 50,000 people?

A)0.3255
B)0.3986
C)0.0417
D)0.1867

Question 37

Assume that the average talk time on an Apple iPhone is 20 hours and that this time follows the exponential probability distribution. What is the probability that a randomly selected iPhone will experience less than 15 hours of talk time?

A)0.4252
B)0.2555
C)0.3184
D)0.5276

Question 38

The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. What is the probability that a randomly selected exam will require between 14 and 19 minutes to grade?

A)0.4477
B)0.3175
C)0.3804
D)0.5837

Question 39

DLP projectors are used in the majority of cinema projection systems and require a special light bulb to display a picture. Assume that the average life of a DLP bulb is 2,000 hours and that this failure time follows the exponential distribution. What is the probability that a randomly selected bulb will last less than 1,800 hours?

A)0.7774
B)0.4056
C)0.5934
D)0.3567

Question 40

Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. The interval around the mean that contains 95% of the airfares is -------.

A)$318.70, $455.70
B)$284.45, $489.95
C)$250.20, $524.20
D)$352.95, $421.45

Question 41

The shape of the exponential distribution is ------.

A)right-skewed
B)left-skewed
C)flat
D)symmetrical

Question 42

Suppose the average tread-life of a certain brand of tire is 42,000 miles and that this mileage follows the exponential probability distribution. What is the probability that a randomly selected tire will have a tread-life between 30,000 and 50,000 miles?

A)0.6959
B)0.5105
C)0.2719
D)0.1854

Question 43

DLP projectors are used in the majority of cinema projection systems and require a special light bulb to display a picture. Assume that the average life of a DLP bulb is 2,000 hours and that this failure time follows the exponential distribution. What is the probability that a randomly selected bulb will last between 1,500 and 2,200 hours?

A)0.3648
B)0.2530
C)0.1395
D)0.1956

Question 44

The time that customers wait to be served at the delicatessen for a grocery store follows the uniform distribution between 0 and 7 minutes. What is the mean of this distribution?

A)4.5
B)1.5
C)3.5
D)2.5

Question 45

The time that customers wait to be served at the delicatessen for a grocery store follows the uniform distribution between 0 and 7 minutes. What is the probability that a randomly selected customer will wait more than 4 minutes at the deli?

A)0.1429
B)0.2857
C)0.5714
D)0.4286

Question 46

The shape of the uniform probability distribution is ------.

A)symmetrical
B)flat
C)right-skewed
D)left-skewed

Question 47

During the 3 PM to 5 PM time period, cars arrive at a bank's drive-through window at an average rate of 15 customers per hour. Assume that the time between arrivals follows the exponential distribution. What is the average time between customer arrivals?

A)4 minutes
B)15 minutes
C)10 minutes
D)30 minutes

Question 48

During the 2013 Major League Baseball season, the St. Louis Cardinals averaged 41,602 fans per home game. Suppose attendance during the season follows the normal probability distribution with a standard deviation of 9,440 per game. What is the probability that a randomly selected game during the 2013 season had an attendance between 25,000 and 35,000 people?

A)0.4218
B)0.2028
C)0.3655
D)0.5860

Question 49

The time for a professor to grade an exam is normally distributed with a mean of 16.3 minutes and a standard deviation of 4.2 minutes. What is the probability that a randomly selected exam will require more than 15 minutes to grade?

A)0.5664
B)0.3783
C)0.4548
D)0.6217

Question 50

The ------ probability distribution describes data where all the values have the same chance of occurring.

A)discrete
B)normal
C)uniform
D)exponential

Question 51

According to the MIT Airline Data Project, American Airlines controlled 15.5% of the domestic market during a recent year. A random sample of 125 domestic passengers that year was selected. Using the normal approximation to the binomial distribution, what is the probability that more than 12 passengers from this sample were on American Airline flights?

A)0.7995
B)0.9207
C)0.9554
D)0.6368

Question 52

Assume that the amount of time that it takes an employee to service a car at an oil change facility follows the uniform probability distribution between 21 and 38 minutes. What is the probability that a randomly selected car will require more than 30 minutes to service?

A)0.3720
B)0.1687
C)0.4706
D)0.2244

Question 53

Assume that the average talk time on an Apple iPhone is 20 hours and that this time follows the exponential probability distribution. What is the probability that a randomly selected iPhone will experience between 10 and 30 hours of talk time?

A)0.3834
B)0.4650
C)0.5875
D)0.5219

Question 54

Assume that the flight time for U.S. Airways flight 1267 from Philadelphia to Dallas follows the uniform probability distribution between 210 and 250 minutes. What is the probability that a randomly selected flight will take more than 225 minutes?

A)0.700
B)0.625
C)0.195
D)0.361

Question 55

John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. What is the probability that the commute time for a randomly selected day will be more than 30 minutes?

A)0.0885
B)0.0401
C)0.2578
D)0.1977

Question 56

Bob's golf score at his local course follows the normal distribution with a mean of 92.1 and a standard deviation of 3.8. What is the probability that the score on his next round of golf will be more than 90?

A)0.7088
B)0.5832
C)0.6591
D)0.9370

Question 57

The ------- probability distribution is used to describe data where lower values tend to dominate and higher values don't occur very often.

A)binomial
B)exponential
C)uniform
D)normal

Question 58

The ------- is used to find the probability that a continuous uniform random variable will fall between two particular values.

A)uniform cumulative distribution function
B)uniform probability density function
C)continuous uniform probability density function
D)uniform probability distribution

Question 59

Assume that the amount of time that it takes an employee to service a car at an oil change facility follows the uniform probability distribution between 21 and 38 minutes. What is the mean of this distribution?

A)26.5
B)29.5
C)28.0
D)31.0

Question 60

Bananas are sold in bunches at a grocery store and typically consist of 4-8 bananas per bunch. Suppose the weight of these bunches follows a normal distribution with a mean of 3.54 pounds and a standard deviation of 0.63 pounds. What is the probability that a randomly selected bunch of bananas will weigh less than 4.0 pounds?

A)0.7673
B)0.6808
C)0.5080
D)0.9821

Question 61

DLP projectors are used in the majority of cinema projection systems and require a special light bulb to display a picture. Assume that the average life of a DLP bulb is 2,000 hours and that this failure time follows the exponential distribution. What is the probability that a randomly selected bulb will last more than 2,500 hours?

A)0.2031
B)0.2865
C)0.1365
D)0.4492

Question 62

John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a standard deviation of 5.1 minutes. What is the probability that the commute time for a randomly selected day will be between 28 and 34 minutes?

A)0.4013
B)0.2266
C)0.3249
D)0.1335

Question 63

According to Pew Research Center, 71% of Internet users accessed video-sharing sites last month. A random sample of 50 Internet users was selected. Using the normal approximation to the binomial distribution, what is the probability that fewer than 40 people from this sample access video-sharing sites?

A)0.5675
B)0.9406
C)0.6293
D)0.8944

Question 64

Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. What is the probability that a randomly selected airfare between these two cities will be between $325 and $425?

A)0.2650
B)0.3875
C)0.5274
D)0.1548

Question 65

A survey conducted last year asked employed adults from age 25 to 70 if they plan to keep a foot in the working world after retirement. Thirty-three percent of the respondents answered "very likely". A random sample of 75 adults from this age group was asked the same question. Using the normal approximation to the binomial distribution, what is the probability that 21 or fewer adults from this sample would very likely plan to keep a foot in the working world after retirement?

A)0.1075
B)0.3192
C)0.4721
D)0.2119

Question 66

According to Bureau of Labor Statistics, 26.0% of the total part- time workforce in the U.S. was between the ages of 25 and 34 during a recent month. A random sample of 90 part- time employees was selected during this quarter. Using the normal approximation to the binomial distribution, what is the probability that exactly 23 people from this sample were between the ages of 25 and 34?

A)0.2394
B)0.0951
C)0.1615
D)0.0419

Question 67

The normal probability distribution can be used to approximate the ------ distribution when np c 5 and nq c 5.

A)uniform
B)exponential
C)binomial
D)Poisson

Question 68

During the 3 PM to 5 PM time period, cars arrive at a bank's drive-through window at an average rate of 15 customers per hour. Assume that the time between arrivals follows the exponential distribution. What is the probability that a randomly selected customer will arrive less than 5 minutes after the previous customer?

A)0.4246
B)0.5477
C)0.8831
D)0.7135

Question 69

A survey conducted in 2011 asked employed adults from age 25 to 70 if they plan to keep a foot in the working world after retirement. Thirty-three percent of the respondents answered "very likely". A random sample of 75 adults from this age group was asked the same question. Using the normal approximation to the binomial distribution, what is the probability that more than 18 adults from this sample would very likely plan to keep a foot in the working world after retirement?

A)0.8413
B)0.9370
C)0.5557
D)0.6772

Question 70

During the 2013 Major League Baseball season, the St. Louis Cardinals averaged 41,602 fans per home game. Suppose attendance during the season follows the normal probability distribution with a standard deviation of 9,440 per game. What is the probability that a randomly selected game during the 2013 season had an attendance fewer than than 55,000 people?

A)0.5610
B)0.6523
C)0.7788
D)0.9222

Question 71

According to Bureau of Labor Statistics, 26.0% of the total part-time workforce in the U.S. was between the ages of 25 and 34 during a recent month. A random sample of 90 part-time employees was selected during this quarter. Using the normal approximation to the binomial distribution, what is the probability that fewer than 19 people from this sample were between the ages of 25 and 34?

A)0.2530
B)0.4149
C)0.3879
D)0.1190

Question 72

According to the Bureau of Labor Statistics, 7.1% of the labor force was recently unemployed. A random sample of 100 employable adults was selected. Using the normal approximation to the binomial distribution, what is the probability that fewer than 11 people from this sample are unemployed?

A)0.8217
B)0.9066
C)0.6539
D)0.5574

Question 73

Assume that the amount of time that it takes an employee to service a car at an oil change facility follows the uniform probability distribution between 21 and 38 minutes. What is the probability that a randomly selected car will require between 25 and 35 minutes to service?

A)0.6425
B)0.5882
C)0.4133
D)0.3216

Question 74

According to the Bureau of Labor Statistics, 7.1% of the labor force was recently unemployed. A random sample of 100 employable adults was selected. Using the normal approximation to the binomial distribution, what is the probability that exactly 8 people from this sample are unemployed?

A)0.4333
B)0.1452
C)0.0681
D)0.3512

Question 75

Assume that the flight time for U.S. Airways flight 1267 from Philadelphia to Dallas follows the uniform probability distribution between 210 and 250 minutes. What is the mean of this distribution?

A)235
B)230
C)240
D)245

Question 76

According to Pew Research Center, 71% of Internet users accessed video-sharing sites last month. A random sample of 50 Internet users was selected. Using the normal approximation to the binomial distribution, what is the probability that exactly 36 people from this sample access video-sharing sites?

A)0.4286
B)0.2005
C)0.3669
D)0.1217

Question 77

According to Pew Research Center, 71% of Internet users accessed video-sharing sites last month. A random sample of 50 Internet users was selected. Using the normal approximation to the binomial distribution, what is the probability that 37 or more people from this sample access video-sharing sites?

A)0.2676
B)0.3783
C)0.4602
D)0.1492

Question 78

A discrete random variable that follows the Poisson distribution with a mean equal to 2 has a counterpart continuous random variable that follows the ------- distribution with a mean equal to µ = 1/2.

A)normal
B)uniform
C)discrete
D)exponential

Question 79

The time that customers wait to be served at the delicatessen for a grocery store follows the uniform distribution between 0 and 7 minutes. What is the probability that a randomly selected customer will wait between 1 and 5 minutes at the deli?

A)0.2857
B)0.1429
C)0.4286
D)0.5714

Question 80

The ------- probability distribution is useful when the majority of the data tend to be in the middle of the distribution.

A)normal
B)Poisson
C)exponential
D)uniform