It's in Objective C! Sorry about that!

2. Write the main, function call, and function sumNavg that has three type double input parameters (n1, n2, n3) and two output parameters (n4, n5). The function computes the sum and the average of its three input arguments and relays its results through two output parameters. In essence, input parameters are pass by value (no pointer), and output parameters are pass by reference (pointers)