programming language is c++

Question 3 Write a program that asks the user for the number of students in the class. The program then calls a function named computeTotal. This function should calculate and return the sum of all grades in the class. Use this function to prompt to the user for each grade. The program then calls a function named computeAverage. The number of students and the total grade should be used as a parameter of the computeAverage function. The function computes the average grade in the class, and returns the calculated average to the main program. The main program displays the average grade. Please provide 4 test cases at least. 3.1) Copy and paste the source code. 3.2) Provide one screenshot