CVCX Standard Deviation Calculation

[MercySakesAlive]

What does the math look like that gets me from the "standard deviation by count" in A to the "standard deviation by round" in B. I get that I have to find the average SD by count weighted by their frequencies, but what do I do with that number to get the standard deviation by round amount.

Or maybe this is a flawed question. The numbers in the "standard deviation by count" column A. Those represent numbers of standard deviations at that count? For example, at a count of 1, there is 1.154 average standard deviations? Blergh.

CVCX SD SCreenshot.jpg

[DSchles]

See BJA3, p. 20.

Don

[MercySakesAlive]

Will do.

[Three]

You can't add standard deviations. You must do a weighted sum of variances (the square of SD) and then take the square root in order to add SDs.

[MercySakesAlive]

cool I'll spend some time working on it this weekend