Question

I do not understand how to figure this out:

Calculate variance:

Answer 1

isnt it the sum of the X's squared divided by n or the sample?

Answer 2

I think, but how about this:

calculate range:
-1, 0, 1, 0, -1, 0, 1, 0, -1, 0, 1, 0 is it:

1, 0, 1, 0, 1, 0 , 1, 0, 1, 0, 1, 0:

but how do you do the rest if this is right?

Answer 3

I think I confused myself. I do not want to calculate range but variance. In order to get the variance what do I do?

Answer 4

First calculate the mean

Then for each data value, take the difference between that data value and the mean and square it.

Add up all those squared differences and divide by the number of data values

e.g. for 1,2,3,4 the mean is (1+2+3+4)/4 = 2.5
variance = ( (1-2.5)^2 + (2-2.5)^2 + (3-2.5)^2 + (4-2.5)^2 )/4 = 1.25