1.IPOs - initial public offerings of stock - create billions of dollars of new wealth for owners, managers, and employees of companies that were previously privately owned. Nevertheless, hundreds of large and thousands of small companies remain privately owned. The revenues of a random sample of 15 firms from Forbes 441 Largest Private Companies list is given in the table below.

Company Revenue (in billions)

Enterprise Rent-A-Car $ 13.10

Flying J 14.32

Tenaska Energy 11.60

Wawa 5.05

Ergon 4.49

Brookshire Grocery 2.20

BrightStar 3.66

Bose 2.18

Mary Kay 2.40

LL Bean 1.62

Rooms to Go 1.75

SAS Institute 2.15

Blue Tee 1.10

Printpack 1.36

US Oil 2.19

a.Describe the population from which the random sample was drawn.

b.Use a 98% confidence interval to estimate the mean revenue of the population of companies in question.

c.Interpret your confidence interval in the context of the problem.

d.What characteristic must the population process to ensure the appropriateness of the estimation procedure used in part b.

e.Suppose Forbes reports that the true mean revenue of the 441 companies on the list is $5.0 billion. Is the claim believable?