# Statistics MCQs – Discrete Distributions Part 4

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61. Forty percent of the passengers who fly on a certain route do not check in any luggage. The planes on this route seat 20 passengers. What is the probability that 9 or more passengers on a full flight do not check in their luggage?

a. 0.610

b. 0.095

c. 0.944

d. 0.404

e. 0.869

Answer: D

62. Thirty percent of the passengers who fly on a certain route do not check in any luggage. The planes on this route seat 15 passengers. What is the probability that 9 or more passengers on a full flight check in their luggage?

a. 0.610

b. 0.095

c. 0.944

d. 0.404

e. 0.869

Answer: E

63. If X ~B (6,0.25) , what is P (X > 3) ?

a. 0.038

b. 0.004

c. 0.071

d. 0.148

e. 0.031

Answer: A

64. If X ~B (6,0.40) , what is P (X > 5) ?

a. 0.038

b. 0.004

c. 0.071

d. 0.148

e. 0.031

Answer: B

65. If X ~B (7,0.25) , what is P (X > 3) ?

a. 0.038

b. 0.004

c. 0.071

d. 0.148

e. 0.031

Answer: C

66. If X ~B (7,0.20) , what is P (X > 2) ?

a. 0.038

b. 0.004

c. 0.071

d. 0.148

e. 0.031

Answer: D

67. If X ~B (5,0.50) , what is P (X > 4) ?

a. 0.038

b. 0.004

c. 0.071

d. 0.148

e. 0.031

Answer: E

68. Assume that it is known that 80 % of monkeys treated with a specific antibiotic recover from a particular disease. If 5 monkeys are treated, find the probability that at least 4 monkeys recover.

a. 0.672

b. 0.328

c. 0.263

d. 0.737

e. 0.583

Answer: D

69. An important part of the customer service responsibilities of a telephone company relates to the speed with which problems in residential service can be repaired. Suppose past data indicate that the probability is 0.5 that problems in residential service can be repaired on the same day. On a given day 5 problems were reported. What is the probability that at least three problems will be repaired on the same day?

a. 0.500

b. 0.031

c. 0.187

d. 0.583

e. 0.261

Answer: A

70. It is known that three out of every ten financial institutions prefer debt-financing to equity-financing. A random sample of twenty financial institutions was selected. What is the probability that at least eight financial institutions prefer debt-financing to equity-financing?

a. 0.7720

b. 0.1130

c. 0.1144

d. 0.2280

e. 0.8870

Answer: D

71. A large manufacturing company that produces CD players believes that 1 out of every 20 CD players is defective. To ensure quality control, a random sample of 120 CD players were selected and tested. A large quality control investigation would be launched if more than 10 out of the 120 CD players selected are defective. What is the expected number of non-defective CD players out of the sample of 120 CD players?

a. 6

b. 114

c. 5

d. 95

e. 120

Answer: B

72. A large manufacturing company that produces CD players believes that 1 out of every 20 CD players is defective. To ensure quality control, a random sample of 120 CD players were selected and tested. A large quality control investigation would be launched if more than 10 out of the 120 CD players selected are defective. What is the expected number of defective CD players out of the sample of 120 CD players?

a. 6

b. 114

c. 5

d. 95

e. 120

Answer: A

73. A large manufacturing company that produces CD players believes that 1 out of every 20 CD players is defective. To ensure quality control, a random sample of 100 CD players were selected and tested. A large quality control investigation would be launched if more than 10 out of the 100 CD players selected are defective. What is the expected number of non-defective CD players out of the sample of 100 CD players?

a. 6

b. 114

c. 5

d. 95

e. 120

Answer: D

74. A large manufacturing company that produces CD players believes that 1 out of every 20 CD players is defective. To ensure quality control, a random sample of 100 CD players were selected and tested. A large quality control investigation would be launched if more than 10 out of the 100 CD players selected are defective. What is the expected number of defective CD players out of the sample of 100 CD players?

a. 6

b. 114

c. 5

d. 95

e. 120

Answer: C

75. At a wholesale protea nursery exactly 100 seeds are planted in each seed-bed, and the probability

that a protea seed will germinate is 0.8. What is the expected number of seeds in the seed-bed that will germinate?

a. 80

b. 96

c. 75

d. 160

e. 65

Answer: A

76. At a wholesale protea nursery exactly 120 seeds are planted in each seed-bed, and the probability

that a protea seed will germinate is 0.8. What is the expected number of seeds in the seed-bed that will germinate?

a. 80

b. 96

c. 75

d. 160

e. 65

Answer: B

77. At a wholesale protea nursery exactly 100 seeds are planted in each seed-bed, and the probability

that a protea seed will germinate is 0.75. What is the expected number of seeds in the seed-bed that will germinate?

a. 80

b. 96

c. 75

d. 160

e. 65

Answer: C

78. At a wholesale protea nursery exactly 200 seeds are planted in each seed-bed, and the probability

that a protea seed will germinate is 0.8. What is the expected number of seeds in the seed-bed that will germinate?

a. 80

b. 96

c. 75

d. 160

e. 65

Answer: D

79. At a wholesale protea nursery exactly 100 seeds are planted in each seed-bed, and the probability

that a protea seed will germinate is 0.65. What is the expected number of seeds in the seed-bed that will germinate?

a. 80

b. 96

c. 75

d. 160

e. 65

Answer: E

80. What is the expected number of heads in 100 tosses of an unbiased coin?

a. 100

b. 25

c. 50

d. 75

e. 0

Answer: C