Facebook: A study showed that two years ago, the mean time spent per visit to Facebook was 20.8 minutes. Assume the standard deviation is o = 8.0 minutes. Suppose that a simple random sample of 105 visits was selected this year and has a sample mean of x = 21.8 minutes. A social scientist is interested to know whether the mean time of Facebook visits has changed. Use the a =0.01 level of significance and the critical value method with the table. (a) State the appropriate null and alternate hypotheses. (b) Compute the value of the test statistic. (c) State a conclusion. Use the a = 0.01 level of significance. Part: 0 / 5 Part 1 of 5 (a) State the null and alternate hypotheses. H: This hypothesis test is a (Choose one) v test