The original population of X's was:

1, 2, 3, 3, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9, 10, 11

21 random samples of size five were taken.
The mean of each sample was calculated and listed below:

5,  4.8,  5.8,  4.4,  4.6,  5.4,  5,  6,  5.4,  7.4,  5.8,  5.8,  4.8,  6,  6,  5.6,  6.2,  7.2,  6.8,  6.8,  4.8

This forms a new population of X-bar's (the distribution of sample means).

Find the mean of this population.

Find the standard deviation of this population.

Other questions to ask yourself:

Since the mean of the original population (of X's) is 6, why isn't the mean of the X-bars the same?

The standard deviation of the original population (of X's) is 2.31455.  According to the formula given in class, the standard deviation of the X-bar's should be .955.   Why isn't the standard deviation you calculated equal to .955?

If you have time, use minitab to check out the shapes of the two distributions above by looking at their stem and leaf plots.