The expressing quantity based on the number of members of a group varies from the value of mean for the group is called a standard deviation SD. The pooled standard deviation is the weighted average of each group's standard deviation and it is the average spread of all data points about their group mean and is the. The below given is the Pooled standard deviation formula for determining the pooled estimate of standard deviation in simple on your own.

Mean = Sum of data values / N(Number of Values)

Where,

n

s

k=Number of group

M=Mean

This Pooled standard deviation formula page shows provides you the individual formulas for the calculation of the pooled estimate of standard deviation and also for the mean.