The J.O. Supplies Company buys calculators from a Korean supplier. The probability of a

defective calculator is 10%.

If 100 calculators are selected at random, what is the expected number of defectives?

A. 9

B. 90

C. 10

D. 95

The J.O. Supplies Company buys calculators from a Korean supplier. The probability of a

defective calculator is 10%.

If 100 calculators are selected at random, what is the standard deviation of the number of

defectives?

A. 9.00

B. 3.17

C. 9.49

D. 3.00

Historical data shows that the average number of patient arrivals at the intensive care unit

of General Hospital is 3 patients every 2 hours. Assume that the patient arrivals are distributed

according to Poisson distribution.

Determine the probability of 6 patients arriving in a five-hour period.

A. .136

B. .109

C. .246

D. .001

Historical data shows that the average number of patient arrivals at the intensive care unit

of General Hospital is 3 patients every 2 hours. Assume that the patient arrivals are distributed

according to Poisson distribution.

Determine the probability of at least 4 but no more than 8 patients arriving in a three-hour

period.

A. .3813

B. .5711

C. .4276

D. .7861

E. .6174

During off hours, cars arrive at a tollbooth on the East-West toll road at an average rate of

0.5 cars per minute. The arrivals are distributed according to the Poisson distribution.

What is the probability that during the next five minutes three cars will arrive?

A. .2138

B. .1804

C. .0126

D. .0613

For a binomial process, the probability of success is 40% and the number of trials is 5.

Find the expected value.

A. 5.0

B. 1.2

C. 2.0

D. 1.1

For a binomial process, the probability of success is 40% and the number of trials is 5.

Find the variance.

A. 5.0

B. 1.2

C. 2.0

D. 1.1

For a binomial process, the probability of success is 40% and the number of trials is 5.

Find the standard deviation.

A. 5.0

B. 1.2

C. 2.0

D. 1.1

A lawyer believes that the probability is .3 that she can win a discrimination suit. If she

wins the case she will make $40,000, but if she loses she gets nothing. Assume that she has to

spend $5000 preparing the case. What is her expected gain?

A. $35,000

B. $7,000

C. $10,500

D. $9,000

The Post Office has established a record in a major Midwestern city for delivering 90% of

its local mail the next working day. If you mail eight local letters, what is the probability that

all of them will be delivered the next day.

A. 1.0

B. .4305

C. .8131

D. .5695

A car wash loses $30 on rainy days and makes $120 on days when it does not rain. If the

probability of rain is 0.15, calculate the car wash's expected profit.

A. $90

B. $76.50

C. $106.50

D. $97.50

A large disaster cleaning company estimates that 30% of the jobs it bids on are finished

within the bid time. Looking at a random sample of 8 jobs that is has contracted:

Calculate the probability that exactly 4 of the jobs were not completed within the bid time.

A. .0081

B. .2401

C. .0113

D. .1361

A large disaster cleaning company estimates that 30% of the jobs it bids on are finished

within the bid time. Looking at a random sample of 8 jobs that is has contracted:

Calculate the mean number of jobs completed within the bid time.

A. 4.0

B. 2.4

C. 2.0

D. 5.6

Suppose that x has a hypergeometric distribution with N = 10, r = 5 and n = 3. Calculate

the standard deviation of the distribution.

A. 0.583

B. 0.764

C. 1.500

D. 0.778

If in a hypergeometric distribution r is 300, N = 600 and n = 150, estimate the binomial

probability of success.

A. 0.500

B. 0.333

C. 0.083

D. 0.250

According to data from the state blood program, 40% of all individuals have group A

blood. If six (6) individuals give blood, find the probability

At least 3 of the individuals have group A blood.

A. .8208

B. .5443

C. .4557

D. .1792