The nth Fibonacci number is defined by the following recursive equations: f(1) = 0; R(2) = 1; f(n) = f(n-1) + f(n-2) Therefore the 3rd Fibonacci number is calculated: f(3) = f(2) + f(1) = 1 + 0 = 1, and so forth for higher numbers. Write a function file to calculate nth Fibonacci number; n is an integer input to the function file and the Fibonacci number is the output argument. Use a for loop to perform the calculation