1-Repair Cost for Microwave OvensThe average repair cost of a microwave oven is $55, with a standard deviation of $8. The costs are normally distributed. Find the probability that the mean of the repair bills will be greater than $70.

a.

0.266

b.

0.0152

c.

0.1528

d.

0.0301

2-Investment advisors agree that near-retirees, defined as people aged 55 to 65, should have balanced portfolios. Most advisors suggest that the near-retirees have no more than 50% of their investments in stocks. However, during the huge decline in the stock market in 2008, 15% of near-retirees had 90% or more of their investments in stocks (P. Regnier, "What I Learned from the Crash,"Money, May 2009, p. 114). Suppose you have a random sample of 12 people who would have been labeled as near-retirees in 2008. What is the probability that during 2008:

two or more had 90% or more of their investment instocks?

a.

p =0.6131

b.

p =0.3831

c.

p =0.3188

d.

p =0.5565

3-When 2 dice are rolled, find the probability of getting asum less than 4 or greater than 8

a.

0.3611

b.

0.5667

c.

0.4445

d.

0.2319

e.

0.2778

4-College Education and Business World Success

R. H. Bruskin Associates Market Research found that 20% of Americans do not think that having a college education is important to succeed in the business world. If a random sample of five Americans is selected, find the following probability.

At most 3 people will agree with that statement.

a.

P(At most 3 people will agree) =0.91296

b.

P(At most 3 people will agree) =0.993

c.

P(At most 3 people will agree) =0.9856

d.

P(At most 3 people will agree) =0.3524

5-The probability that a customer will buy a car and an extended warranty is 0.18. If the probability that a customer will purchase a car is 0.45, find the probability that the customer will also purchase the extended warranty.

a.

0.53

b.

0.20

c.

0.72

d.

0.40