Could someone please help me with part d?:
a. Find the average rate of change in the diameter for surface areas between 20 in.squared and 10 in.squared
  answer= 0.0739
b. Find the average rate of change in the diameter when the surface area decreases from 16 in.squared to 14 in.squared
  answer: 0.0729 ​
Part 3
c. Find the average rate of change in D when A increases from 14.9 in.squared to 15.1 in.squared​, and find the average rate of change in D when A increases from 14.99 in.squared to 15.01 in.squared
The average rate of change in D when A increases from 14.9 in.squared to 15.1 in.squared is
  answer= 0.0728.
The average rate of change in D when A increases from 14.99 in.squared to 15.01 in.squared is
  answer=0.0728.
d. Describe a pattern in parts​ a, b, and c.
As the range of areas centered around A=equals {answer} in.squared ​narrows, the average rate of change in the diameter stabilizes to about {answer}.