Calcite | Level 5

How to estimate the standard deviation of the difference between two means?

Hello!

I've trying to estimate the SD of the difference between two means. I have the means, SD and n for each dataset. Below an example of how I have my dataset. I'd appreciate any help with this. Thanks!

 ages sex n mean A SD A mean B SD B Mean diff 19-30 males 882 7.45825 2.619444 6.2115 2.150556 -1.24675 19-30 females 897 5.58875 2.156296 4.666 1.774074 -0.92275 31-50 males 2077 7.591 2.546296 6.32325 2.089815 -1.26775 31-50 females 2288 5.83275 2.173704 4.86975 1.78963 -0.963
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Super User

Re: How to estimate the standard deviation of the difference between two means?

Diamond | Level 26

Re: How to estimate the standard deviation of the difference between two means?

Your table seems to be just the summary statistics. If you have the raw data, then PROC TTEST does this easily, see figure 125.4 here: https://documentation.sas.com/doc/en/pgmsascdc/9.4_3.4/statug/statug_ttest_gettingstarted02.htm

If you don't have the raw data, the formula for pooled standard deviation is given in many textbooks, web sites and even at Wikipedia, and I urge you to do a search to find the proper formula.

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Paige Miller
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