Suppose That in a Group of Six Athletes There Are $\sigma_{\bar{x}}$

Essay

Suppose that in a group of six athletes there are three jockeys whose heights are 60,65 , and 55 inches, and three basketball players whose heights are 80,75 , and 85 inches.
-List all possible random samples of size 2 which may be taken from this population. Calculate the means of these samples, and calculate $\sigma_{\bar{x}}$ .