Final answer:
After plugging in x = 3 into the function f(x) = 12(4)^(x-1), the function value is calculated as f(3) = 12(4)^2 = 192.
Step-by-step explanation:
The student has asked to evaluate the function f(x) = 12(4)x-1 at x = 3 without using a calculator. To do so, we substitute 3 for x in the function. This results in f(3) = 12(4)3-1 = 12(4)2 = 12(16) = 192. The function value for f(3) is 192, calculated by simple exponentiation and multiplication.