Chapter 9, Problem 35PS

We Are Social and Hootsuite reported that the typical American spends 2.02 hours (121 minutes) per day accessing the internet via mobile devices.

In order to test the validity of this statement, you select a sample of 30 friends and family. The results for the time spent per day accessing the internet via mobile devices (in minutes) are stored in InternetMobileTime.

a. Is there evidence that the population mean time spent per day accessing the internet via mobile devices is different from 121 minutes? Use the p-value approach and a level of significance of 0.05.

b. What assumption about the population distribution is needed in order to conduct the t test in (a)?

c. Make a list of the various ways you could evaluate the assumption noted in (b).

d. Evaluate the assumption noted in (b) and determine whether the test in (a) is valid.