The standard deviation for a data set is 0. Determine whether each conclusion about the data is true or false.



a. The standard deviation measures the variation of the data. If the standard deviation is 0, then there is some variation, so all the data are different.




b. All the data must be equal to the mean because the sum of the squares of the differences of the data from the mean is 0. So, all the data take the same value.