Summation function in excel

Question

I tried using this:

SQRT( SUM( POWER(C3:C22 - 378.9, 2) )/20)

But I am getting 17.4, But STDEV.S gives ~72.46

Here are datapoints:

175 373 304 411 411 384 457 330 362 448 394 403 420 377 513 374 392 425 364 261

Answer 1

Your formula is the same one used by STDEV.P. However, you should press Ctrl+Shift+Enter when you are on the cell of your formula because it is an array formula. You should get 70.63.

If you divide by 19 (instead of 20), you'll get the result of STDEV.S