9.5 Hypothesis Testing for Mean o Unknown Using the Critical Value and Rejection Region (t-test) You wish to test the following claim (Ha) at a significance level of a = 0.01. Ho: u = 68.2 Ha: u # 68.2 You believe the population is normally distributed, but you do not know the standard deviation. You obtain a sample of size n = 29 with a mean of a - 76.2 and a standard deviation of s = 11.9. a.) This test is left-tailed right-tailed two-tailed b.) At a = 0.01, the critical value = + (use 3 decimal places) c.) The test statistic = (use 2 decimal places) d.) The test statistic is... O in the critical region O not in the critical region e. ) This test statistic leads to a decision to... O reject the null hypothesis O accept the null hypothesis O fail to reject the null hypothesis