Answer
Rate of Change: $2$
For every extra hour of study, the grade increases by $2$.
Work Step by Step
The formula for Constant rate of change is $\frac{△y}{△x}$. Let's take 2 sets of coordinates and plug it in to this formula.
$\frac{87 - 85}{6 - 5} = \frac{2}{1} = 2$
The constant rate of change is $2$.
As you can see, for every extra hour studied, the grade increases by $2$, which is what the constant rate of change mean.
