I have been reading up on how to calculate variance for different situations and the following has me confused…..
If I take a number of samples (e.g. choose 5 kids in a class and ask them how many pets they have), each time I go into a class and choose 5 kids I am going to get a different mean number of pets, and then each sample will have its own variance.
If I then took the mean of all my samples and added them up and then divided them by the number of the sample I had I'd get the mean of the means.
The part I don't understand is how do I calculate the variance of the mean of means ?
Do I subtract the each mean from the mean of means, square the answer and then divide by n ?