Identify the function that best models the data.

Question

Quantity: 4,6,8,10,12

Profit: 115.50,225,395.50,627,919.50

Possible answers:

A) C(i) = 7.625x^2 - 21.5x + 79.5

B) C(i) = 79.5x^2 - 7.625x + 21.5

C) C(i) = 79.5x + 7.625

D) C(i) = 7.625x + 79.5

Also, is the equation linear, constant, cubic, or quadratic? I think it is constant but I’m not totally sure.

Answer 1

A) C(i) = 7.625x² - 21.5x + 79.5

is the correct answer

I started off graphing it on the graphing calculator. Visually, it looked like a quadratic to me from the graph. I did a quadratic regression on the TI-84 and the equation in A) is the output it provided for a,b and c values.