17. What is the mean?
a 12.41
b. 13.61
c. 12.51
d. 13.71
18. What is the range?
a 15
b. 15.5
c. 25
d. 25.5
19. What is the mean deviation of the data?
a 5
b. 5.10
c. 5.20
d. 5.30
20. What is the standard deviation?
a 5.16
b. 6.11
c. 6.12
d. 6.15​