The constant of proportionality is the same as the slope of a line!
To find slope, we use the equation [tex]\frac{y2-y1}{x2-x1}[/tex]
Let's solve it!
y2 - y1 looks like ... 81.9 - 35.1
which equals 46.8
x2 - x1 looks like ... 7-3
which equals 4
Now we divide 46.8 by 4 to find the constant of proportionality (the slope)
[tex]\frac{46.8}{4} = 11.7[/tex]
11.7 is the answer!
