# Weighted Standard Deviation in Excel [duplicate]

I have a dataset in excel that looks like this:

Impressions Clicks  CTR
2      2    1
5      4  0.8
14      5  0.357142857
2481574  2946  0.00118715
4835785  7453  0.001541218
6224189 10903  0.001751714
5364316  7595  0.001415838
4445746  7003  0.001575214
3789942  3881  0.001024026
3015085  3290  0.00109118
2795202  2823  0.001009945
2727213  2976  0.001091224
2770730  3318  0.001197518
2770752  3932  0.001419109
2467906  3515  0.001424284
1842635  3470  0.001883173
1714929  3833  0.002235078
1642027  3808  0.002319085
1688948  4123  0.002441165
2210116  5298  0.002397159
1758368  4485  0.002550661
48611    55  0.001131431
1     0  0
1     0  0
1     0  0
1     0  0
1     0  0
5     0  0
2     0  0
1     0  0


I want to determine the weighted standard deviation of the CTR column In Excel. For example there are examples of CTR being 0 but that's because the number of impressions is only 1 so it really doesn't justify the variance let alone the mean.

Does anyone know a formula in excel that can do this? I am looking specifically for an Excel formula not just a mathematical formula.

• stats.stackexchange.com/search?q=weighted+variance
– whuber
Commented Aug 9, 2018 at 19:01
• Questions that are specifically about software are not on-topic here.
– whuber
Commented Aug 9, 2018 at 19:05
• Thanks @whuber where should i ask that type of question? Commented Aug 9, 2018 at 19:05
• Sites that focus on Excel might be best. You could link to formulas on our site for a reference and ask how to implement them in Excel.
– whuber
Commented Aug 9, 2018 at 19:06