Answer:
f(9.5) = 558.02.
Step-by-step explanation:
Because it is an exponential function, it can be written: y = (a)(b)^x
Now substitute in the two known points:
72 = (a)(b)^7.5 and
2 = (a)(b)^4 : => since 2 = (a)(b)^2 divide the left side by 2 and the right by (a)(b)^2
72/2 =[(a)(b)^7.5]/[(a)(b)^4]: => the (a) cancels out and b becomes b^(7.5–4)
36 = b^3.5: => To isolate b take the 3.5 root of both sides
{3.5 root}(36) = {3.5 root}(b^3.5)
2.783927 = b
Now to solve for a
2 = (a)(b)^4 => 2 = (a)(2.783927)^4 => 2 = (a)(60.066375) divide both sides by 60.066375 0.0332965 = a
Equation: y = (0.0332965)(2.783927)^x
Now plug in 9.5 for x
(0.0332965)(2.783927)^9.5 = 558.0178525 = 558.02
