Chapter 1.2, Problem 71E

Electricity rates. Table 3 shows the electricity rates charged by Monroe Utilities in the summer months. The base is a fixed monthly charge, independent of the kWh (kilowatt-hours) used during the month.

1. (A)   Write a piecewise definition of the monthly charge S(x) for a customer who uses x kWh in a summer month.
2. (B)   Graph S(x).

Table 3 Summer (July–October)

Base charge, $8.50

First 700 kWh or less at 0.0650/kWh

Over 700 kWh at 0.0900/kWh