Asked by Jessica

The table below shows the average diameter of a pupil in a person's eye as he or she gets older.

age (years). Average Pupil Diameter (mm)
20 4.7
30 4.3
40 3.9
50 3.5
60 3.1
70 2.7
80 2.3

What is the average rate of change, in millimeters per year, of a person's pupil diameter from age 20 to 80?
Answered by Ms. Sue
How do you think you can solve this problem?

Answered by Jessica
add all the diameters divided by the sum of the ages?
Answered by Ms. Sue
Nope. The question asks for the rate of change. Note that the diameter decreased 0.4 mm every 10 years.

6 * 0.4 = _______ mm

Divide the product by 60 to find the average change per year.




Answered by Jessica
Where did you get 6 from?
Answered by Ms. Sue
There are six decades listed; six changes in diameter.



Answered by kd
ANSWER: D: -0.04

Explanation: Average rate of change is the same as slope

2.3 - 4.7/80 - 20 = -2.4/60 = -0.04