In late 2007, it was reported that 79% of U.S. adults owned a cell phone (data extracted from E.C. Baig, "Tips Help Navigate Tech-Buying Maze", USA Today, November 28, 200, p.5B). Suppose that by the end of 2009, that percentage was 85%. If a sample of 10 U.S. adults is selected, what is the probability that:
a). P(X = 8)
b). P(X ? 8)
c.) P(X ? 10)
d.) Provide a substantive answer to the question.