Average and Standard Deviation without outliers in Excel
September 2nd, 2011
Sometimes you need the average and standard deviation of a dataset without a certain amount of outliers.
For example you want the average or standard deviation without the top 2.5% datapoints
{=AVERAGE(IF((DataRng<LARGE(DataRng,ROUNDUP((COUNT(DataRng)*0.025),0))),DataRng))}
{=STDEV.P(IF((DataRng<LARGE(DataRng,ROUNDUP((COUNT(DataRng)*0.025),0))),DataRng))}
If you want the average without the top 10 and bottom 10 datapoints this would be your solution
{=AVERAGE(IF((DataRng<LARGE(DataRng,10))*(DataRng>SMALL(DataRng,10)),DataRng))}
happy averaging or standard deviating