a. To test the following hypotheses, a statistics practitioner randomly sampled 100 observations and found and s  35. Calculate the test statistic (and for Excel users, the p-value) of a test to determine whether there is enough evidence at the 1% significance level to infer that the alternative hypothesis is true.

b. Repeat part

(a) with s  25.

c. Repeat part

(a) with s  15.

d. Discuss what happens to the t-statistic (and for Excel users, the p-value) when the standard deviation decreases.