In a NiCd battery, a fully charged cell is composed of nickelic hydroxide. Nickel is an element that has multiple oxidation states. Assume the following proportions of the states:

Nickel Charge                        Proportions Found

0……………………………………………...0.17

+2…………………………………………….0.35

+3…………………………………………….0.33

+4…………………………………………….0.15

(a) Determine the cumulative distribution function of nickel charge.

(b) Determine the mean and variance of the nickel charge.