A sample of charge accounts at a local drug store revealed the following frequency distribution of unpaid balances.
Unpaid Balance Frequency
10 - 29 1
30 - 49 6
50 - 69 9
70 - 89 11
90 - 109 13
a. Determine the mean unpaid balance.
b. Determine the variance.
c. Determine the standard deviation.
d. Compute the coefficient of variation.