Answer:
The percent change in the cost of electricity from coal-fired to hydroelectric power = 54.5% reduction.
Step-by-step explanation:
a) The cost of coal-fired power = $0.11 per KWh
b) The cost of hydroelectric power = $0.05 per KWh
c) The reduction or savings = $0.06 ($0.11 - $0.05) per KWh
d) The % change is therefore = $0.06/$0.11 x 100 = 54.5%
e) The implication is that it will cost a typical house 54.5% less when it switches from coal-fired power plants to hydroelectric power. The house will be paying $0.06 less per KWh.