>>373
#include <stdio.h>

int main(void)
{
    double d[] = {50.5, 75.0, 62.0, 65.5, 80.0, 95.0, 90.5, 87.0, 80.0, 99.5};
    double sum, *ptr = d;
    int i, n;

    n = sizeof(d) / sizeof(double); /* n = 10; */

    for(i = 0, sum = 0.0; i < n; i++){
        sum += *(ptr + i);
    }
    printf("%f", sum / n);
    return 0;
}