1-) A study by the Web metrics firm Experian showed that in August of 2018, the mean time spent per visit to INSTAGRAM was 20.8 minutes with a population standard deviation of 8 minutes. Suppose a simple random sample of 60 visits in August 2020 has a mean of 21.5 minutes. A social scientist is interested to know whether the meantime of INSTAGRAM visits has changed. Use ? = 0.05. Show all steps.

1.State the Null and Alternative Hypothesis

2-) Find the Standard Error of the Mean?M= ?

?n

3-) Find the Standard Error Z-Score (STANDARD SCORE) SEz-score= M-?

?m

4-) Use the Alpha-Level Z-Score & STANDARD SCORE to Accept or Reject H0 (sketch the graph