In late 2007, it was reported that 79% of U.S. adults owned a cell phone (data extracted

Question:

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, 2007, 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. 8 own a cell phone?
b. At least 8 own a cell phone?
c. All 10 own a cell phone?
d. If you selected the sample in a particular geographical area and found that none of the 10 respondents owned a cell phone, what conclusion might you reach about whether the percentage of cell phone owners in this area was 85%?