Suppose your statistics instructor gave six examinations during the semester

Suppose your statistics instructor gave six examinations during the semester. You received the following grades (percent correct): 90, 73, 87, 89, 92, and 74. Instead of averaging the six scores, the instructor indicated he would randomly select three grades and compute the final percent correct based on the three percents.

(a) How many different samples, without replacement, of three test grades are possible?

(c) Compute the mean of the sample means and compare it to the population mean. (Round your answers to 3 decimal places.)


The mean of the sample means is 
The population mean is