The amount of time Americans spend watching television is closely monitored by ﬁrms such as A. C. Nielsen because this helps to determine advertising pricing for commercials.
(a) Do you think the variable “weekly time spent watching television” would be normally distributed? If not, what shape would you expect the variable to have?
(b) According to the American Time Use Survey, adult Americans spend 2.35 hours per day watching television on a weekday. Assume that the standard deviation for “time spent watching television on a weekday” is 1.93 hours. If a random sample of 40 adult Americans is obtained, describe the sampling distribution of x, the mean amount of time spent watching television on a weekday.
(c) Determine the probability that a random sample of 40 adult Americans results in a mean time watching television on a weekday of between 2 and 3 hours.
(d) One consequence of the popularity of the Internet is that it is thought to reduce television watching. Suppose that a random sample of 35 individuals who consider themselves to be avid Internet users results in a mean time of 1.89 hours watching television on a weekday. Determine the likelihood of obtaining a sample mean of 1.89 hours or less from a population whose mean is presumed to be 2.35 hours. Based on the result obtained, do you think avid Internet users watch less television?