Suppose your statistics instructor gave six examinations during the semester. You received the following grades (percent correct): 81, 70, 89, 90, 92, and 77. Instead of averaging the six scores, the instructor indicated he would randomly select five grades and compute the final percent correct based on the five percents.
(a) How many different samples, without replacement, of five test grades are possible?
(b) Compute the mean of the sample means and compare it to the population mean. (Round your answers to 3 decimal places.)