Chapter 2.4, Problem 50E

Commercial electrical usage The monthly charge (in dollars) for x kilowatt hours (kWh) of electricity used by a commercial customer is given by the following function.

$C(x)=\{\begin{array}{l}7.25+0.1079x\text{if}0\le x\le 5\\ 19.22+0.1079x\text{if}5<x\le 750\\ 20.795+0.1058x\text{if}750<x\le 1500\\ 131.345+0.0321x\text{if}x>1500\end{array}$

Find the monthly charges for the following usages.

$\text{5kWh}$

(b) $\text{6}\text{kWh}$

(c) $\text{3000kWh}$