Question

Consider the following data set: 3,4,6,7,9,9,11

If 5 were added to each of the values, how would that affect the standard deviation (no need to do any calculation, but be sure to explain why.)

Answer 1

The standard deviation measures how spread out the data is (from the center mean). Adding 5 to each value will NOT change the standard deviation at all. The entire distribution will be shifted 5 units to the right, but will retain the same shape and spread. Only the center will change.