Sentences were chosen at random from Sun Tzu's book The Art of War. The number of words in the sentences were counted. This is the result.

21

18

18

20

18

19

8

7

13

14

11

11

23

23

14

14

14

15

3

23

9

23

15

18

Problem:

Use the data above to: a) determine the mean and sample standard deviation, b) calculate a 95% margin of error, c) determine the respective confidence interval.