Code

// A program that will store five students' marks in an array
// It will output all the marks for verification
// It will also calculate and report the average mark
// Marc Chee 12/03/2019

#include <stdio.h>

int main (void) {
    int marks[5] = {0};
    int counter;
    
    // commented out the manual entry to keep it as a reference
/*    // manually input marks
    marks[0] = 55;
    marks[1] = 84;
    marks[2] = 72;
    marks[3] = 44;
    marks[4] = 59; */
    
    // Ask the user to input the 5 marks
    printf("Please enter five separate marks.\n");
    counter = 0;
    while(counter < 5) {
        scanf("%d", &marks[counter]);
        counter++;
    }
    
    // loop through array and print out values
    counter = 0;
    while(counter < 5) {
        printf("%d\n", marks[counter]);
        counter++; // counter = counter + 1
    }
    
    // loop through the array and accumulate the values into a total
    int total = 0;
    counter = 0;
    while(counter < 5) {
        total += marks[counter];
        counter++;
    }    
    printf("Total of all marks is %d\n", total);
    
    // calculate and output the average
    double average = total/5.0;
    printf("The average mark was: %lf\n", average);
    
    return 0;
}