1. Calculate the variance of the set of data to two decimal places. { 1,2,4,4,5,6,6}

a. 22
b. 4
c.3.14
d. 1/7
e.2

Explanation:

First we need the arithmetic mean

Add up the values to get 1+2+4+4+5+6+6 = 28

Divide this over the number of values (n = 7) to get 28/n = 28/7 = 4

The mean is 4.

Next, we subtract the mean from each data value and square the difference

Add up those results: 9+4+0+0+1+4+4 = 22

Lastly, we divide over the number of items (n = 7) to get the population variance: 22/n = 22/7 = 3.14 approximately

Side note:

If you wanted the sample variance, then you divide over n-1 = 7-1 = 6

22/(n-1) = 22/6 = 3.67 is the approximate sample variance