A high school student weighed 145 lbs in 1986 and weighed 190 lbs in 2007. Find the average rate of change, include units. Interpret the meaning of your answer.(calculator allow)

Answer 1

The average rate of change is just { f(x₂) - f(x₁) }/(x₂ - x₁) = (190-145)/(2007-1986) = 45/21 = 2.143 lbs/year

The form is just (y₂-y₁)/(x₂-x₁) which is the slope if you think of y = f(x).

This gives you the linear approximation each year of the weight gain.