Business statistics !! PLEASE READ

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 1

MS1023 Business Statistics w/Comp Apps I

Homework #2 – Use Red Par Score Form

Chp. 5: Questions 1-50

1. The volume of liquid in an unopened 1-

gallon can of paint is an example of

_________.

a) the binomial distribution

b) both discrete and continuous variable

c) a continuous random variable

d) a discrete random variable

e) a constant

2. The number of defective parts in a lot of

25 parts is an example of _______.

a) a discrete random variable

b) a continuous random variable

c) the Poisson distribution

d) the normal distribution

e) a constant

A market research team compiled the

following discrete probability distribution.

In this distribution, x represents the number

of automobiles owned by a family.

x P(x)

0 0.10

1 0.10

2 0.50

3 0.30

Answer questions 3-5 based on the above

discrete probability distribution.

3. The mean (average) value of x is _____.

a) 1.0

b) 1.5

c) 2.0

d) 2.5

e) 3.0

4. The standard deviation of x is ________.

a) 0.80

b) 0.89

c) 1.00

d) 2.00

e) 2.25

5. Which of the following statements is true?

a) This distribution is skewed to the right.

b) This is a binomial distribution.

c) This is a normal distribution.

d) This distribution is skewed to the left.

e) This distribution is bimodal.

6. Twenty five items are randomly selected

from a batch of 1000 items. Each of these

items has the same probability of being

defective. The probability that exactly 2 of

the 25 are defective could best be found by

_______.

a) using the normal distribution

b) using the binomial distribution

c) using the Poisson distribution

d) using the exponential distribution

e) using the uniform distribution

7. A fair coin is tossed 5 times. What is the

probability that exactly 2 heads are

observed?

a) 0.313

b) 0.073

c) 0.400

d) 0.156

e) 0.250

Pinky Bauer, Chief Financial Officer of

Harrison Haulers, Inc., suspects

irregularities in the payroll system, and

orders an inspection of a random sample of

vouchers issued since January 1, 2006. A

sample of ten vouchers is randomly selected,

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 2

without replacement, from the population of

2,000 vouchers. Each voucher in the sample

is examined for errors and the number of

vouchers in the sample with errors is

denoted by x.

Answer questions 8-11 based on the above

information.

8. If 20% of the population of vouchers

contain errors, P(x = 0) is _____________.

a) 0.8171

b) 0.1074

c) 0.8926

d) 0.3020

e) 0.2000

9. If 20% of the population of vouchers

contain errors, P(x > 0) is _____________.

a) 0.8171

b) 0.1074

c) 0.8926

d) 0.3020

e) 1.0000

10. If 20% of the population of vouchers

contains errors, the mean value of x is ____.

a) 400

b) 2

c) 200

d) 5

e) 1

11. If 20% of the population of vouchers

contains errors, the standard deviation of x is

______.

a) 1.26

b) 1.60

c) 14.14

d) 3.16

e) 0.00

12. If x is a binomial random variable with

n=8 and p=0.6, what is the probability that x

is equal to 4?

a) 0.500

b) 0.005

c) 0.124

d) 0.232

e) 0.578

13. If x is a binomial random variable with n

= 12 and p = 0.45, P(4 ≤ x ≤ 6) is _______?

a) 0.1700

b) 0.2225

c) 0.2124

d) 0.5838

e) 0.6048

14. If x is a binomial random variable with

n=10 and p=0.6, P(x ≥ 6) is _______?

a) 0.6177

b) 0.2508

c) 0.3823

d) 0.6331

e) 0.3669

15. If x is a binomial random variable with

n=20 and p=0.3, P(x > 8) is _______?

a) 0.0654

b) 0.2277

c) 0.8867

d) 0.1144

e) 0.1133

16. If x is a binomial random variable with

n=20 and p=0.9, P(x ≤ 16) is _______?

a) 0.0867

b) 0.0432

c) 0.1330

d) 0.8670

e) 0.0898

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 3

According to Cerulli Associates of Boston,

30% of all CPA financial advisors have an

average client size between $500,000 and

$1 million. Thirty-four percent have an

average client size between $1 million and

$5 million. Suppose a complete list of all

CPA financial advisors is available and 18

are randomly selected from that list.

Answer the questions 17-22 based on the

above information.

17. What is the expected number of CPA

financial advisors that have an average

client size between $500,000 and $1

million?

a) 0.30

b) 0.612

c) 6.12

d) 5.40

e) 0.54

18. What is the expected number with an

average client size between $1 million and

$5 million?

a) 0.34

b) 6.12

c) 0.612

d) 5.40

e) 0.54

19. What is the probability that at least eight

CPA financial advisors have an average

client size between $500,000 and $1

million?

a) 0.1407

b) 0.0811

c) 0.0596

d) 0.9404

e) 0.8593

20. What is the probability that two, three, or

four CPA financial advisors have an

average client size between $1 million and

$5 million?

a) 0.0229

b) 0.0630

c) 0.1217

d) 0.7924

e) 0.2076

21. What is the probability that none of the

CPA financial advisors have an average

client size between $500,000 and $1

million?

a) 0.0006

b) 0.9994

c) 0.0016

d) 0.0084

e) 0.0126

22. What is the probability that none have

an average client size between $1 million

and $5 million?

a) 0.0016

b) 0.9994

c) 0.0084

d) 0.0006

e) 0.0126

23. The number of cars arriving at a toll

booth in five-minute intervals is Poisson

distributed with a mean of 3 cars arriving in

five-minute time intervals. The probability

of 5 cars arriving over a five-minute interval

is _______.

a) 0.0940

b) 0.0417

c) 0.1500

d) 0.1008

e) 0.2890

24. The number of cars arriving at a toll

booth in five-minute intervals is Poisson

distributed with a mean of 3 cars arriving in

five-minute time intervals. The probability

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 4

of 3 cars arriving over a five-minute interval

is _______.

a) 0.2700

b) 0.0498

c) 0.2240

d) 0.0001

e) 0.0020

25. Suppose that, for every lot of 100

computer chips a company produces, an

average of 1.4 are defective. Another

company buys many lots of these chips at a

time, from which one lot is selected

randomly and tested for defects. If the tested

lot contains more than three defects, the

buyer will reject all the lots sent in that

batch. What is the probability that the buyer

will accept the lots? Assume that the defects

per lot are Poisson distributed.

a) 0.9463

b) 0.0537

c) 0.1128

d) 0.2417

e) 0.3452

A medical researcher estimates that .00004

of the population has a rare blood disorder.

If the researcher randomly selects 100,000

people from the population,

Answer questions 26-27 based on the

above information using Poisson

Approximation to Binomial problems.

26. What is the probability that seven or

more people will have the rare blood

disorder?

a) 0.0298

b) 0.0511

c) 0.8894

d) 0.0595

e) 0.1106

27. What is the probability that more than 10

people will have the rare blood disorder?

a) 0.0081

b) 0.9972

c) 0.0019

d) 0.0028

e) 0.9919

A high percentage of people who fracture or

dislocate a bone see a doctor for that

condition. Suppose the percentage is 99%.

Consider a sample in which 300 people are

randomly selected who have fractured or

dislocated a bone.

Answer questions 28-30 based on the

above information using Poisson

Approximation to Binomial problems.

28. What is the expected number of people

who would not see a doctor?

a) 297

b) 3

c) 30

d) 300

e) 1

29. What is the probability that exactly five

of them did not see a doctor?

a) 0.0504

b) 0.9161

c) 0.1008

d) 0.1680

e) 0.8992

30. What is the probability that fewer than

four of them did not see a doctor?

a) 0.1680

b) 0.8153

c) 0.1008

d) 0.2528

e) 0.6472

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 5

31. Assume that a random variable has a

Poisson distribution with a mean of 5

occurrences per ten minutes. The number of

occurrences per hour follows a Poisson

distribution with λ equal to _________

a) 5

b) 60

c) 30

d) 10

e) 20

32. The Poisson distribution is being used to

approximate a binomial distribution. If

n=40 and p=0.06, what value of lambda

would be used?

a) 0.06

b) 2.4

c) 0.24

d) 24

e) 40

33. The number of phone calls arriving at a

switchboard in a 10 minute time period

would best be modeled with the _________.

a) binomial distribution

b) hypergeometric distribution

c) Poisson distribution

d) hyperbinomial distribution

e) exponential distribution

34. The number of defects per 1,000 feet of

extruded plastic pipe is best modeled with

the ________________.

a) Poisson distribution

b) Pascal distribution

c) binomial distribution

d) hypergeometric distribution

e) exponential distribution

35. The hypergeometric distribution must be

used instead of the binomial distribution

when ______

a) sampling is done with replacement

b) sampling is done without replacement

c) n≥5% N

d) both b and c

e) there are more than two possible

outcomes

36. The probability of selecting 3 defective

items and 7 good items from a warehouse

containing 10 defective and 50 good items

would best be modeled with the _______.

a) binomial distribution

b) hypergeometric distribution

c) Poisson distribution

d) hyperbinomial distribution

e) exponential distribution

Circuit boards for wireless telephones are

etched, in an acid bath, in batches of 100

boards. A sample of seven boards is

randomly selected from each lot for

inspection. A batch contains two defective

boards; and x is the number of defective

boards in the sample.

Answer questions 37-39 based on the above

information.

37. P(x=1) is _______.

a) 0.1315

b) 0.8642

c) 0.0042

d) 0.6134

e) 0.6789

38. P(x=2) is _______.

a) 0.1315

b) 0.8642

c) 0.0042

d) 0.6134

e) 0.0034

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 6

39. P(x=0) is _______.

a) 0.1315

b) 0.8642

c) 0.0042

d) 0.6134

e) 0.8134

40. A large industrial firm allows a discount

on any invoice that is paid within 30 days.

Of all invoices, 10% receive the discount.

In a company audit, 10 invoices are sampled

at random. The probability that fewer than 3

of the 10 sampled invoices receive the

discount is approximately __________.

a) 0.1937

b) 0.057

c) 0.001

d) 0.3486

e) 0.9298

41. In a certain communications system,

there is an average of 1 transmission error

per 10 seconds. Assume that the distribution

of transmission errors is Poisson. The

probability of 1 error in a period of one-half

minute is approximately ________.

a) 0.1493

b) 0.3333

c) 0.3678

d) 0.1336

e) 0.03

42. It is known that screws produced by a

certain company will be defective with

probability .01 independently of each other.

The company sells the screws in packages of

25 and offers a money-back guarantee that

at most 1 of the 25 screws is defective.

Using Poisson approximation for binomial

distribution, the probability that the

company must replace a package is

approximately _________

a) 0.01

b) 0.1947

c) 0.7788

d) 0.0264

e) 0.2211

On Monday mornings, the First National

Bank only has one teller window open for

deposits and withdrawals. Experience has

shown that the average number of arriving

customers in a four-minute interval on

Monday mornings is 2.8, and each teller can

serve more than that number efficiently.

These random arrivals at this bank on

Monday mornings are Poisson distributed.

Answer the questions 43-50 based on the

above information.

43. What is the probability that on a Monday

morning exactly six customers will arrive in

a four-minute interval?

a) 0.9756

b) 0.0872

c) 0.9593

d) 0.0163

e) 0.0407

44. What is the probability that no one will

arrive at the bank to make a deposit or

withdrawal during a four-minute interval?

a) 0.9392

b) 0.1703

c) 0.0608

d) 0.0000

e) 0.8297

45. Suppose the teller can serve no more

than four customers in any four-minute

interval at this window on a Monday

morning. What is the probability that, during

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 7

any given four-minute interval, the teller

will be unable to meet the demand?

a) 0.8477

b) 0.1523

c) 0.1557

d) 0.8443

e) 0.3081

46. Suppose the teller can serve no more

than four customers in any four-minute

interval at this window on a Monday

morning. What is the probability that the

teller will be able to meet the demand?

a) 0.8477

b) 0.1557

c) 0.8443

d) 0.1523

e) 0.3081

47. When demand cannot be met during any

given interval, a second window is opened.

What percentage of the time will a second

window have to be opened?

a) 0.8477

b) 0.8443

c) 0.1557

d) 0.1523

e) 0.3081

48. What is the probability that exactly three

people will arrive at the bank during a two-

minute period on Monday mornings to make

a deposit or a withdrawal?

a) 0.1082

b) 0.0026

c) 0.2225

d) 0.1128

e) 0.0407

49. What is the probability that five or more

customers will arrive during an eight minute

period?

a) 0.1523

b) 0.0143

c) 0.6579

d) 0.3421

e) 0.8477

50. On Saturdays, cars arrive at Sami

Schmitt's Scrub and Shine Car Wash at the

rate of 6 cars per fifteen minute interval.

Using the Poisson distribution, the

probability that five cars will arrive during

the next five minute interval is

_____________.

a) 0.1008

b) 0.0361

c) 0.1339

d) 0.1606

e) 0.3610

Chp. 6: Questions 51-100.

51. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then the height of this distribution, f(x), is …

a) 1/8

b) 1/4

c) 1/12

d) 1/20

e) 1/24

52. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then the mean of this distribution is _____.

a) 10

b) 20

c) 5

d) 0

e) unknown

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 8

53. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then the standard deviation of this

distribution is __________________.

a) 4.00

b) 1.33

c) 1.15

d) 2.00

e) 1.00

54. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then the probability, P(9  x  11), is ____.

a) 0.250

b) 0.500

c) 0.333

d) 0.750

e) 1.000

55. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then the probability, P(10.0  x  11.5), is _.

a) 0.250

b) 0.333

c) 0.375

d) 0.500

e) 0.750

56. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then the probability, P(13  x  15), is

__________________.

a) 0.250

b) 0.500

c) 0.375

d) 0.000

e) 1.000

57. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then P(x < 7) is __________________.

a) 0.500

b) 0.000

c) 0.375

d) 0.250

e) 1.000

58. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then P(x  11) is ________.

a) 0.750

b) 0.000

c) 0.333

d) 0.500

e) 1.000

59. If x is uniformly distributed over the

interval 8 to 12, inclusively (8  x  12),

then P(x  10) is __________________.

a) 0.750

b) 0.000

c) 0.333

d) 0.500

e) 0.900

60. If a continuous random variable x is

uniformly distributed over the interval 8 to

12, inclusively, then P(x = exactly 10) is __.

a) 0.750

b) 0.000

c) 0.333

d) 0.500

e) 0.900

61. The normal distribution is an example of

a) a discrete distribution

b) a continuous distribution

c) a bimodal distribution

d) an exponential distribution

e) a binomial distribution

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 9

62. The total area underneath any normal

curve is equal to _______.

a) the mean

b) one

c) the variance

d) the coefficient of variation

e) the standard deviation

63. The area to the left of the mean in any

normal distribution is equal to _______.

a) the mean

b) 1

c) the variance

d) 0.5

e) -0.5

64. A standard normal distribution has the

following characteristics:

a) the mean and the variance are both equal

to 1

b) the mean and the variance are both equal

to 0

c) the mean is equal to the variance

d) the mean is equal to 0 and the variance is

equal to 1

e) the mean is equal to the standard

deviation

65. If x is a normal random variable with

mean 80 and standard deviation 5, the z-

score for x = 88 is ________.

a) 1.8

b) -1.8

c) 1.6

d) -1.6

e) 8.0

66. Suppose x is a normal random variable

with mean 60 and standard deviation 2. A z

score was calculated for a number, and the z

score is 3.4. What is x?

a) 63.4

b) 56.6

c) 68.6

d) 53.2

e) 66.8

67. Suppose x is a normal random variable

with mean 60 and standard deviation 2. A z

score was calculated for a number, and the z

score is -1.3. What is x?

a) 58.7

b) 61.3

c) 62.6

d) 57.4

e) 54.7

68. Let z be a normal random variable with

mean 0 and standard deviation 1. What is

P(z < 1.3)?

a) 0.4032

b) 0.9032

c) 0.0968

d) 0.3485

e) 0. 5485

69. Let z be a normal random variable with

mean 0 and standard deviation 1. What is

P(1.3 < z < 2.3)?

a) 0.4032

b) 0.9032

c) 0.4893

d) 0.0861

e) 0.0086

70. Let z be a normal random variable with

mean 0 and standard deviation 1. What is

P(z > 2.4)?

a) 0.4918

b) 0.9918

c) 0.0082

d) 0.4793

e) 0.0820

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 10

71. Let z be a normal random variable with

mean 0 and standard deviation 1. What is

P(z < -2.1)?

a) 0.4821

b) -0.4821

c) 0.9821

d) 0.0179

e) -0.0179

72. Let z be a normal random variable with

mean 0 and standard deviation 1. What is

P(z > -1.1)?

a) 0.36432

b) 0.8643

c) 0.1357

d) -0.1357

e) -0.8643

73. Let z be a normal random variable with

mean 0 and standard deviation 1. What is

P(-2.25 < z < -1.1)?

a) 0.3643

b) 0.8643

c) 0.1235

d) 0.4878

e) 0.5000

74. The expected (mean) life of a particular

type of light bulb is 1,000 hours with a

standard deviation of 50 hours. The life of

this bulb is normally distributed. What is

the probability that a randomly selected bulb

would last longer than 1150 hours?

a) 0.4987

b) 0.9987

c) 0.0013

d) 0.5013

e) 0.5513

75. The expected (mean) life of a particular

type of light bulb is 1,000 hours with a

standard deviation of 50 hours. The life of

this bulb is normally distributed. What is the

probability that a randomly selected bulb

would last fewer than 1100 hours?

a) 0.4772

b) 0.9772

c) 0.0228

d) 0.5228

e) 0.5513

76. The expected (mean) life of a particular

type of light bulb is 1,000 hours with a

standard deviation of 50 hours. The life of

this bulb is normally distributed. What is

the probability that a randomly selected bulb

would last fewer than 940 hours?

a) 0.3849

b) 0.8849

c) 0.1151

d) 0.6151

e) 0.6563

77. Suppose you are working with a data set

that is normally distributed with a mean of

400 and a standard deviation of 20.

Determine the value of x such that 60% of

the values are greater than x.

a) 404.5

b) 395.5

c) 405.0

d) 395.0

e) 415.0

According to a report by Scarborough

Research, the average monthly household

cellular phone bill is $60. Suppose local

monthly household cell phone bills are

normally distributed with a standard

deviation of $11.35.

Answer questions 78-81 based on the above

information.

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 11

78. What is the probability that a randomly

selected monthly cell phone bill is more than

$85?

a) 0.4861

b) 0.9861

c) 0.6139

d) 0.5000

e) 0.0139

79. What is the probability that a randomly

selected monthly cell phone bill is between

$45 and $70?

a) 0.8106

b) 0.9066

c) 0.7172

d) 0.4066

e) 0.3106

80. What is the probability that a randomly

selected monthly cell phone bill is between

$65 and $75?

a) 0.2366

b) 0.1700

c) 0.4066

d) 0.0934

e) 0.6700

81. What is the probability that a randomly

selected monthly cell phone bill is no more

than $40?

a) 0.4987

b) 0.4608

c) 0.5000

d) 0.9608

e) 0.0392

82. According to Student Monitor, a New

Jersey research firm, the average cumulated

college student loan debt for a graduating

senior is $25,760.Assume that the standard

deviation of such student loan debt is

$5,684. Thirty percent of these graduating

seniors owe more than what amount?

a) $28,715.68

b) $2,955.68

c) $22,804.32

d) $28,809.28

e) $28,359.68

83. Let x be a binomial random variable

with n=20 and p=.8. If we use the normal

distribution to approximate probabilities for

this, we would use a mean of _______.

a) 20

b) 16

c) 3.2

d) 8

e) 5

84. Let x be a binomial random variable

with n=100 and p=.8. If we use the normal

distribution to approximate probabilities for

this, a correction for continuity should be

made. To find the probability of more than

12 successes, we should find _______.

a) P(x>12.5)

b) P(x>12)

c) P(x>11.5)

d) P(x<11.5)

e) P(x < 12)

A study about strategies for competing in

the global marketplace states that 52% of the

respondents agreed that companies need to

make direct investments in foreign

countries. It also states that about 70% of

those responding agree that it is attractive to

have a joint venture to increase global

competitiveness. Suppose CEOs of 95

manufacturing companies are randomly

contacted about global strategies.

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 12

Using Normal Approximation of Binomial

Distribution with correction for continuity,

answer questions 85-88 based on above

information.

85. What is the probability that between 44

and 52 (inclusive) CEOs agree that

companies should make direct investments

in foreign countries?

a) 0.3869

b) 0.2389

c) 0.6258

d) 0.5013

e) 0.7389

86. What is the probability that more than 56

CEOs agree with that assertion?

a) 0.4279

b) 0.8279

c) 0.5000

d) 0.0721

e) 0.5721

87. What is the probability that fewer than

60 CEOs agree that it is attractive to have a

joint venture to increase global

competitiveness?

a) 0.5000

b) 0.0582

c) 0.4418

d) 0.9418

e) 0.5582

88. What is the probability that between 55

and 62 (inclusive) CEOs agree with that

assertion?

a) 0.4963

b) 0.9963

c) 0.3133

d) 0.8099

e) 0.1830

89. The average length of time between

arrivals at a turnpike tollbooth is 23 seconds.

Assume that the time between arrivals at the

tollbooth is exponentially distributed. What

is the probability that a minute or more will

elapse between arrivals?

a) 0.9265

b) 0.0435

c) 0.4365

d) 0.0735

e) 0.5000

90. The average length of time between

arrivals at a turnpike tollbooth is 23 seconds.

Assume that the time between arrivals at the

tollbooth is exponentially distributed. If a

car has just passed through the tollbooth,

what is the probability that no car will show

up for at least 3 minutes?

a) 0.0004

b) 0.9996

c) 0.4996

d) 0.0435

e) 0.9265

During the summer at a small private airport

in western Nebraska, the unscheduled arrival

of airplanes is Poisson distributed with an

average arrival rate of 1.12 planes per hour.

Answer questions 91-93 based on the above

information.

91. What is the average interarrival time

between planes (in minutes)?

a) 53.6

b) 67.2

c) 53.4

d) 60

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 13

e) 58.88

92. What is the probability that at least 2

hours will elapse between plane arrivals?

a) 0.5000

b) 0.8935

c) 0.3935

d) 0.6065

e) 0.1065

93. What is the probability of two planes

arriving less than 10 minutes apart?

a) 0.8297

b) 0.1703

c) 0.6703

d) 0.3297

e) 0.5000

94. The probability that a call to an

emergency help line is answered in less than

10 seconds is 0.8. Assume that the calls are

independent of each other. Using the normal

approximation for binomial with a

correction for continuity, the probability that

at least 75 of 100 calls are answered within

10 seconds is approximately _______

a) 0.8

b) 0.1313

c) 0.5235

d) 0.9154

e) 0.8687

95. Inquiries arrive at a record message

device according to a Poisson process of rate

15 inquiries per minute. The probability that

it takes more than 12 seconds for the first

inquiry to arrive is approximately

_________

a) 0.05

b) 0.75

c) 0.25

d) 0.27

e) 0.73

96. On Saturdays, cars arrive at Sam

Schmitt's Scrub and Shine Car Wash at the

rate of 6 cars per fifteen minute interval. The

probability that at least 2 minutes will elapse

between car arrivals is _____________.

a) 0.0000

b) 0.4493

c) 0.1353

d) 1.0000

e) 1.0225

97. On Saturdays, cars arrive at Sam

Schmitt's Scrub and Shine Car Wash at the

rate of 6 cars per fifteen minute interval. The

probability that less than 10 minutes will

elapse between car arrivals is _________.

a) 0.8465

b) 0.9817

c) 0.0183

d) 0.1535

e) 0.2125

98. Incoming phone calls generally are

thought to be Poisson distributed. If an

operator averages 2.2 phone calls every 30

seconds, what is the expected (average)

amount of time between calls (in seconds)?

a) 66

b) 30

c) 13.64

d) 60

e) 27.27

99. Incoming phone calls generally are

thought to be Poisson distributed. If an

operator averages 2.2 phone calls every 30

seconds, what is the probability that a

minute or more would elapse between

incoming calls?

a) 0.9877

b) 0.5123

MS1023 Business Statistics with Computer Applications Homework #2

Maho Sonmez [email protected] 14

c) 0.4877

d) 0.5000

e) 0.0123

100. Incoming phone calls generally are

thought to be Poisson distributed. If an

operator averages 2.2 phone calls every 30

seconds, what is the probability that at least

two minutes would elapse between

incoming calls?

a) 0.0002

b) 0.9998

c) 0.4998

d) 0.5000

e) 0.5002