A finite population consists of four elements:6,1,5,4.

(a) How many different samples of sizen= 2 can be selected from this population if you sample without replacement? (Sampling is said to bewithout replacementif an element cannot be selected twice for the same sample.)

________ samples

(b) List the possible samples of sizen= 2. (Enter your answers as a comma-separated list. Enter samples in the form (a,b), with the smaller value first.)

(c) Compute the sample mean for each of the samples given in part (b). (Enter your answers as a comma-separated list.)

(d) Find the sampling distribution ofx.