I am doing estimating Standard deviation of grouped data.
I have done all the sum freg 60/ midpoint 2580/ x bar is 43 for all/ and total with x bar is 10260. Can you explain how to get the variance and sq root from these. I know that you have to fregx(mid-xbar)square2 and divide by 60-1. What do I do after that to find variance and sq root. Thank you
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation = square root of variance