Interest Rates?

Question

A credit Manager rates each applicant for a car loan on a scale of 1 throught 5 and then determines the interest rate from the accompanying table. Find the equation of the line in the slope-intercept form that goes throught these points.

1= 24% 2=20% 3=16% 4=12% 5=8%

Answer 1

Question : " 1= 24% 2=20% 3=16% 4=12% 5=8% "
Answer:

y = m*x + c

2 = m * 20 + c (1)
4 = m * 12 + c (2)

(1) - (2)

-2 = m * 8
m = - 1/4

2 = (- 1/4) * 20 + c
2 = -5 * c
c = 7

y = -1/4 x + 7

Answer 2

call the rate x and y the interest rate.
Take the two first points

y-24 =(24-20)/(1-2) *(x-1)

y= -4x +28 The other two poits verify