The fuel capacity in gallons of 50 randomly selected cars is shown here. Class Frequency 1012 .......6

Question:

The fuel capacity in gallons of 50 randomly selected cars is shown here.
Class Frequency
10–12 .......6
13–15 .......4
16–18 .......14
19–21 .......15
22–24 .......8
25–27 .......2
28–30 .......1
50
Find each of these.
a. Mean
b. Modal class
c. Variance
d. Standard deviation