# How to Calculate the Pool standard Deviation

Hello There !

In this lesson I didn't understand how do you calculate the pool standard deviation, can you give me the formula ?

Or is it the same as the one for the pool variance ?

Thanks a lot !

3 answers ( 0 marked as helpful)

Hello Vincent!

Thanks for reaching out!

You can use the one for the variance and then take its squared root.

Best,

The 365 Team

Thanks for quick response, and suggestion for later review of the course, the pooled standard deviation calculation might be included in video, for easy referencing and smooth learning

Robiu,

I agree. That pooled standard deviation came out of left field with no explanation in this example.

For the record, based on the response above, all we had to do was obtain the sqrt of .05, and voila: "pooled standard variation."