What are the variance and standard deviation of {1, 1, 1, 1, 1, 80, 1, 1, 1, 1, 1, 1}?
1 Answer
The population variance is:
and the populations standard deviation is the square root of this value:
Explanation:
First, let's assume that this is the entire population of values. Therefore we are looking for the population variance . If these numbers were a set of samples from a larger population, we would be looking for the sample variance which differs from the population variance by a factor of
The formula for the population variance is
where
In our population the mean is
Now we can proceed with the variance calculation:
and the standard deviation is the square root of this value: