Question

Excluding hydropower, U.S. power plants used renewable energy sources to generate 105 million megawatthours of electricity in 2007. By 2012, the amount of electricity generated had increased to 219 million megawatthours. Let x represent the time (in years) since 2007 and let y represent the number of megawatt hours (inmillions).Because time x is defined in years since 2007, 2007 corresponds to x = 0 and 2012 corresponds to x = 5. Fnd therate of change (slope) of the use of renewable energy sources between 2007 and 2012.

Answer 1

In order to calculate the rate of change, we just need to divide the difference in megawatt hours generated between 2007 and 2012 by the period of 5 years.

So we have that:

`\text{rate}=(219-105)/(5)=(114)/(5)=22.8`

So the rate of change is 22.8 millions of megawatt hours generated per year.