a. A random sample of 25 observations was drawn from a normal population. The sample mean and sample standard deviation are x̄ = 52 and s = 15. Calculate the test statistic of a test to determine if there is enough evidence at the 10% significance level to infer that the population mean is not equal to 50.

b. Repeat part (a) with n = 15.

c. Repeat part (a) with n = 5.

d. Discuss what happens to the t-statistic when the sample size decreases.