Squared differences from the mean

This diagram is similar to that on the previous page but instead of distances from a fixed target, we have distances from the mean. (If you drag crosses, the mean changes.)

The red square is again one whose area is the average of the blue square areas. The population standard deviation is the side length of this square.

The sample standard deviation divides by (n - 1) instead of n.

Drag the crosses to explain the influence of an outlier on the standard deviation. (Make all values similar except for a single outlier.)