Refer to Exercise 4.173 and the August 2011 survey by the Pew Internet & American Life Project. The study found that 40% of adult cell phone owners have downloaded an application ("app") to their cell phone. Assume this percentage applies to the population of all adult cell phone owners.
a. In a random sample of 50 adult cell phone owners, how likely is it to find that more than 60% have downloaded an "app" to their cell phone?
b. Refer to part a. Suppose you observe a sample proportion of .62. What inference can you make about the true proportion of adult cell phone owners who have downloaded an "app"?
c. Suppose the sample of 50 cell phone owners is obtained at a convention for the International Association for the Wireless Telecommunications Industry. How will your answer to part b change, if at all?