How long does it take to download a two-hour movie from the iTunes store? According to Apple's technical support site, support.apple.com/kb/ht1577, downloading such a movie using a 5 M bit/s broadband connection should take 18 to 24 minutes.
Assume that the download times are uniformly distributed between 18 and 24 minutes. If you download a two-hour movie, what is the probability that the download time will be
a. less than 19 minutes?
b. more than 23 minutes?
c. between 20 and 22 minutes?
d. What are the mean and standard deviation of the download times?