Question 1

A road stop has been established during a busy holiday weekend. Historical data has that 6% of drivers will be driving under the influence of alcohol and 15% will not be wearing their seatbelts. What is the probability that a driver is under the influence, and not wearing the seatbelt? (Assume these are independent events.)

Group of answer choices

(1-0.15) * (1-0.06)

(0.15) + (0.06)

(1-0.15)*(0.06)

(0.15) * (0.06)

Question 2

A Material Review Board is being formed to review discrepant material. The Engineering Manager will chair the board. 3 engineers will be selected out of 9 available to also be on the board. How many different ways (combinations) can these engineers be selected?

Group of answer choices

120

126

504

84

28

Question 3

Which of the following is not true of the Poisson distribution?

Group of answer choices

Events which occur can be counted, but events which do not occur cannot be counted.

Events are counted within a defined unit.

The population and sample size must be defined.

None of the above. (All of the above are true.)

Question 4

A roadside shop sells minnows to fisherman. The minnows are kept in a large tank (very large population of minnows) and the worker scoops out a cupful to give to the customer. The average number of fish in a cupful is 24. To determine the probability that there will be less than 20 in a cupful, what distribution should be used?

Group of answer choices

Poisson because I can count the minnows that are in the cup but not count the ones that are not there.

Binomial because I know the average rate of fish in a cup.

Hypergeometric because the probabilities will change with each cup drawn.

Poisson estimation of binomial because the sample size is large and probability is small.

Question 5

1000 parts are produced in a batch on a machine of which 15% in the batch (150 parts) are known to be defective. A sample of 25 parts is taken from the batch. To get the probabilities of getting a given number of defective units in the sample, which distribution should be used?

Group of answer choices

Poisson because I can count the defective units that are there, but not count the ones that are not there.

Hypergeometric because I have a small finite population from which the sample is drawn and the probability of being defective are constant with each part inspected.

Binomial because I have a constant defective rate and parts can be either defective or not defective.

Binomial estimation of hypergeometric because the change in the probability of being defective is very small as each part is taken from the sample for inspection.

Question 6

50 parts are produced in a batch. 15 of the parts in the batch are known to be defective. A sample of 10 parts is taken from the batch. To get the exact probabilities of getting a given number of defective units in the sample, which distribution should be used?

Group of answer choices

Poisson because I can count the defective units that are there, but not count the ones that are not there.

Binomial because I have a constant defective rate and parts can be either defective or not defective.

Hypergeometric because I have a small finite population from which the sample is drawn and the probability of being defective will change with each part inspected.

Binomial estimation of hypergeometric because the change in the probability of being defective is very small as each part is taken from the sample for inspection.

Question 7

A batch of 40 parts contains 10 defective parts. If a sample of 6 is selected. What is the probability of exactly 1 defective part in the sample?

Group of answer choices

(51)(3010)(406)

(61)(0.20)1(0.80)5

(406)(0.20)1(0.80)5

(101)(305)(406)

Question 8

The road works department is creating a budget and must assess the likelihood of accidents at various intersections in the county. A major intersection has averaged 4 reportable accidents per year. What is the probability of no accidents in the next year?

Group of answer choices

0.2212

0.0183

0.7780

Cannot be determined

Question 9

Historically, 76% of customers at a fast food restaurant order a "combo" rather than an individual sandwich. If 20 customers place orders, what is the probability that exactly 12 of them have ordered a combo?

Group of answer choices

0.0515

0.0795

0.1236

0.0414

Question 10

A call center receives, on average, 6 calls per hour on Friday afternoons. What is the probability of having exactly 15 calls in the hours between 1 and 4 pm this Friday?

Group of answer choices

0.079

0.161

0.058

0.126