Click here to download avg.c.

#include <stdio.h>
#include <stdlib.h>

int sum(int* array, int size);

int main() {
  // read size n
  int n;
  do {
    printf("Enter size: ");
    fflush(stdout);
  } while(scanf(" %i", &n) != 1 || n <= 0);

  // allocate array and read in contents
  int* data = calloc(n, sizeof(int));
  printf("Enter %i integers, space separated.\n", n);
  for (int i=0; i<n; ++i) {
    scanf(" %i", &data[i]);
  }

  // CALL YOUR FUNCTION(S) HERE
  double avg = sum(data, n) / (double)n;
  // AND PRINT OUT THE RESULTS
  printf("The average is %g\n", avg);

  // clean-up time
  free(data);
  return 0;
}

int sum(int* array, int size) {
  int tot = 0;
  for (int i=0; i < size; ++i) {
    tot += array[i];
  }
  return tot;
}