Experian Marketing Services reported that the typical American spends a mean of 144 minutes (2.4 hours) per day accessing the Internet via a mobile device. (Source: The 2014 Digital Marketer, available at ex.pn/1kXJjfX.) 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 device (in minutes) are stored in Internet Mobile Time.
a. Is there evidence that the population mean time spent per day accessing the Internet via mobile device is different from 144 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.