Answer:
7.5
Step-by-step explanation:
the slope m is a measure of the rate of change
Calculate m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (6, 45 ) and (x₂, y₂ ) = (9, 67.5 )
m = [tex]\frac{67.5-45}{9-6}[/tex] = [tex]\frac{22.5}{3}[/tex] = 7.5 ← rate of change