For the following list of scores in a sample:

X

19

17

17

20

13

15

10

16

19

13

a. What is the sample mean? (I guessed 5.9, not sure if this is correct?)

b. What is the estimated standard deviation? (I guessed 30.6, not sure if this is correct?)

c. What is the central 95% of scores?

d. What is the central 68% of scores?