Answer:
Her weight is increase by 18 lbs over past five years and the slope is 3.6 lbs per year.
Step-by-step explanation:
Given information: Estelle weight is
At age 16 = 110 lbs
At age 21 = 128 ibs
Increase in her weight over the past 5 years is the difference of weight at age 21 and at age 16.
Increase in her weight over the past 5 years = 128 - 110 = 18
Her weight is increase by 18 lbs over past five years.
Let x=age and y=weight, then the weight function passes through the points (16,110) and (21,128).
If a line passes through two points
and
, then the slope of the line is

Using the above formula we get



Therefore the slope is 3.6 lbs per year.