Question 483338
Somehow this is one of those overused problems that textbooks just like to throw in repeatedly.


Solution is quite simple, to find f(2.5), just replace all occurrences of x with 2.5. Similarly, to find f(12), replace x with 12.


f(2.5) = 28.007 years
f(12) = 76.2241 years


http://www.wolframalpha.com/input/?i=-+0.001718x^4+%2B+0.087326x^3+%E2%80%93+1.3367x^2+%2B+12.46x+%2B+3.914+where+x+%3D+12