The amount of text messages sent in the United States has been steadily declining since its peak in 2011 with 2,304 billion messages sent per year, which is about 960 text messages per month per cell phone owner. This number declined steadily to reach 592 text messages per month per cell phone owner in 2016. Suppose AT&T would like to test the hypothesis that the average number of text messages per month per owner has declined further since 2016. A recent random sample of 75 U.S. cell phone users was selected and the number of text messages sent last month was recorded. These data can be found in the Excel file titled text messages.xlsx. Using α = 0.05, answer the following:

a. State the null and alternative hypothesis.

b. Based on this sample, what conclusions can AT&T make about this population?

c. Determine the precise p-value for this test using Excel.