Find the mean and standard deviation of the population List

Find the mean, and standard deviation of the population. List of the examples of the given size from the population to find the mean of each. The word counts of five essays are 501, 636, 546, 602 and 575. Use a sample size of 2.

Solution

There are 5 essays

Hence 5C2 sample spaces with size 2

{(501,636) (636,546)....}

Let us find mean for these 10 groups

Mean = {568.5,523.5,551.5,538, 591,619,605.5,574,560.5, 588.5}

Population mean will be the mean of all x bars

Hence mu = 572

Std dev of the 10 means = 28.357

Hence population std deviation = 28.357/rt 10

= 8.9673