The amount of time spent by North American adults watching television per day is normally distributed with a mean of 6 hours and a standard deviation of 1.5 hours. a. What is the probability that a randomly selected North American adult watches television for more than 7 hours per day? b. What is the probability that the average time watching television by a random sample of five North American adults is more than 7 hours? c. What is the probability that in a random sample of five North American adults, all watch television for more than 7 hours per day?