The following data represent the number of appointments made per 15-minute interval by telephone solicitation for a lawn-care company. Assume these are population data.

Number of ..... Frequency

Appointments of Occurrence

0–under 1 .....31

1–under 2 .....57

2–under 3 .....26

3–under 4 .....14

4–under 5 ..... 6

5–under 6 ..... 3

a. Calculate the mean of the data.

b. Calculate the mode.

c. Calculate the median.

d. Calculate the variance.

e. Calculate the standard deviation.