check the picture below.
so we know Bethany's payrate, her slope is 11.75, namely $11.75/hr, for for every hour, she makes 11.75 bucks.
now, let's use those red-circled points, to get Grant's slope, and therefore his payrate,
[tex]\bf (\stackrel{x_1}{3}~,~\stackrel{y_1}{38.70})\qquad
(\stackrel{x_2}{7}~,~\stackrel{y_2}{90.30})
\\\\\\
% slope = m
slope = m\implies
\cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{90.30-38.70}{7-3}\implies \cfrac{51.6}{4}\implies 12.9[/tex]
low and behold, Grant makes 12.90 or 12.9 bucks every hour.
well, Bethany does 11.75 hmmm what's their difference?
12.90 - 11.75
1.15
so 12.90 is greater than 11.75 by 1.15, meaning, Grant makes 1.15 bucks more every hour than Bethany.
