calculating a weighted average using formula

[bob green]

I have data from a series of studies in 2 columns of data (G1-G15) &
(H1-H15).

Column 1 = the number positive for an event in each study
Column 2 = the sample size for each study

I calculated a sum for column 1 & column 2 in G16 & H16 respectively.
In addition I want to calculate the average and standard deviation.


The following formula computes an average but I also need the
standard deviation.

=G16*100/H16

Any assistance is appreciated.

Bob

[KL]

Hi Bob,

I guess for Standard Deviation you could use the function STDEV()

I usually calculate the weighted average using the following formula:

=SUMPRODUCT(G1:G15,H1:H15)/SUM(H1:H15)

in your case could also be:

=SUMPRODUCT(G1:G15,H1:H15)/H16

Regards,
KL


"bob green" <[email protected]> wrote in message
news:[email protected]...
>
> I have data from a series of studies in 2 columns of data (G1-G15) &
> (H1-H15).
>
> Column 1 = the number positive for an event in each study
> Column 2 = the sample size for each study
>
> I calculated a sum for column 1 & column 2 in G16 & H16 respectively.
> In addition I want to calculate the average and standard deviation.
>
>
> The following formula computes an average but I also need the
> standard deviation.
>
> =G16*100/H16
>
> Any assistance is appreciated.
>
> Bob
>
>
>