how would you calculate the population variance of a data set given a normal distribution with 45 data points, a mean of 15, median of 15 and sample variance of 7.5?

Question

dumbcow · Answer

the difference between sample variance and pop variance is you divide by N-1 and N respectively
Let X be sum of squared deviations
$$\frac{X}{N-1} = 7.5$$
where N = 45
$$X = (7.5)(44)$$
so pop variance is X/N
$$\frac{X}{45} = \frac{(7.5)(44)}{45}$$

anonymous · Answer

Thank you, that makes sense now.  I was trying to make it much more difficult than it actually is.