参考答案：

#include<iostream>
#include<algorithm>
#include<math.h>
const int N = 10010;
using namespace std;
int a[N];
int main()
{
    int t;
    cin >> t;
    while (t--)
    {
        double fc = 0, sum = 0, avg = 0;
        int n;
        cin >> n;
        for (int i = 0; i < n; ++i)
        {
            cin >> a[i];
            sum += a[i];
        }
        avg = sum / (double)n;
        sort(a, a + n);
        cout << a[n - 1] - a[0] << ' ';
        for (int i = 0; i < n; ++i)
        {
            fc += pow(a[i] - avg, 2);
        }
        printf("%.6lf\n", fc / (double)n);
    }

    return 0;
}