7.126 There are approximately 40,000 travel agencies in the United States, of which 11,000 are members of the American Society of Travel Agents (booking a tour through an ASTA member increases the likelihood of a refund in the event of cancellation).

a. If x is the number of ASTA members among 5000 randomly selected agencies, could you use the methods of Section 7.8 to approximate P(1200 , x , 1400)? Why or why not?

b. In a random sample of 100 agencies, what are the mean value and standard deviation of the number of ASTA members?

c. If the sample size in Part

(b) is doubled, does the standard deviation double? Explain.