A group of high school students have the following scores on a history essay: 8, 9, 9, 10, 10, 10, 11, 11, 12. Before doing the calculation, answer the following questions, and then do the calculations and check your answers.

a. What will be the impact on the value of the standard deviation of these scores of adding another 10? Why is the impact not greater?

b. What will be the impact on the value of the standard deviation of adding a 5? Why is the change to the standard deviation greater than adding a 10?