Write a function averageDigits that computes the average of the digits of a 3-digit positive number in the range (100,999), Use the following function prototype: double averageDigits(int); For example, averageDigits(936) returns 6.0 ((9+3+6)/3). Write a test program that prompts the user to enter a 3-digit number, call the function averageDigits and print the result in the main program. The process is repeated if the user enters y to continue.