The following scores

Question

5, 7, 8, 5, 3, 2, 8, 6, 9, 4, 7, 3

with this data find the variance and Standard deviation. This is for a Population.

Answer 1

The first step is to get the mean. To do that, add all the values and divide my total number of items. In this case it would be adding all the values and diving by 12 to get a mean of 5.58.

Second step is to to calculate the difference of each value from the mean. So, you would write on your paper 5-5.58, 7-5.58, 8-5.58 and so on, for each of the 12 values. Once you get the difference, then you will square each difference and add them together. So you will write on your paper 0.3364 + 2.0164 + 5. 8564 and so on (keep in mind the values I have listed are already squared). The total will be 56.6466. Once you. get this value, it will be like calculating the mean, in that you will divide this by the total number of values, and will give you a variance of 4.72.

Lastly, once you have your variance, you simply take the square root of the variance to get the standard deviation, which in this case is 2.17.

Hope this helps!

Answer 2

average

population variance is

per MS Excel

Yes, for Population Variance you divide the sum of the square of the deviations by N,

rather than N-1