Program for average and some of n numbers

#include<stdio.h>
void main()
{
    int i,sum=0,n,mark[100];
    float avg=0;
    printf("Enter the no.of marks:");
    scanf("%d",&n);
    for(i=0;i<n;i++)
    {
        printf("Enter mark %d :",i+1);
        scanf("%d",&mark[i]);
        sum=sum+mark[i];
    }
    avg=sum/n;
    printf("The sum of marks is %d",sum);
    printf("\nThe average is %f",avg);
    }