Central Limit Theorem

List all samples of size n=2 that can be obtained without replacement.
I have come up with: (2,3)(2,6)(2,8)(2,11)(2,18)(3,6)(3,8)(3,11)(3,18)(6,8)(6,11)(6,18)(8,11)(8,18)(11,18)

List the population of all values of x(bar over it) by finding the mean of each sample.