Math (FST Exponential & Logarithm)
posted by Shay on .
Find the exponential model using y=a(b)^x with (9, 120) & (12, 216) (round to 4 decimal places show work)

subbing in the 2 points gives us
1) 120 = a(b)^9
2) 216 = a(b)^12
divide 2) by 1)
216/120 = b^12/b^9
b^3 = 9/5
b = (9/5)^(1/3) = 1.2164
put this back into 1)
120 = a(1.2164)^9
a = 20.5761
y = 20.5764(1.2164)^x
(I checked for (12,216), it works)