The pooled standard deviation calculator below gives the value of the combined standard deviation of two data sets.
Sample 1
Sample 2
Pooled standard deviation = 7.739852
The pooled standard deviation refers to the combined standard deviation of two different groups of data values. Suppose that we have two data values of sizes n1 and n2 respectively.
If the standard deviations of the two data sets are S1 and S2 respectively, then the pooled standard deviation can be calculated using the formula,
S2 = [(n1-1)S12+(n2-1)S22]/(n1+n2).
The pooled standard deviation is a kind of weighted average of the standard deviations of the two given samples. The pooled variance can be calculated by taking the square of the pooled standard deviation.