A random sample of voters in Nashville, Tennessee, is classified by age group, as shown by the following data.

Age Group Frequency

18–under 24 .........17

24–under 30 .........22

30–under 36 .........26

36–under 42 .........35

42–under 48 .........33

48–under 54 .........30

54–under 60 .........32

60–under 66 .........21

66–under 72 .........15

a. Calculate the mean of the data.

b. Calculate the mode.

c. Calculate the median.

d. Calculate the variance.

e. Calculate the standard deviation.