Media Matrix and Jupiter Communications gathered data on the time adults and the time teens spend online during a month (USA Today, September 14, 2000). The study concluded that on average, adults spend more time online than teens. Assume that a follow-up study sampled 26 adults and 30 teens. The standard deviations of the time online during a month were 94 minutes and 58 minutes, respectively. Do the sample results support the conclusion that adults have a greater variance in online time than teens? Use a=.01. What is the p-value?
This solution calculates the p-value based on a situation in which a hypothesis test is determining whether adults have a greater variance in online time than teens.