#include<bits/stdc++.h>
using namespace std;

#define int long long

void solve() {
    int n;
    cin >> n;

    vector<int> a(n);

    for(int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    int p = -1;
    for(int i = 1; i < n - 1; ++i) {
        if(a[i] > a[i - 1] && a[i] < a[i + 1]) {
            p = i;
            break;
        }
    }

    double ans = 0;

    int sum = 0, num = 0;
    for(int i = 0; i <= p; ++i) {
        sum += a[i];
        num++;
    }
    for(int i = p + 1; i < n; ++i) {
        sum += a[i];
        num++;
        ans = max(ans, 1.0 * sum / num);
    }
    sum = 0, num = 0;
    for(int i = n - 1; i >= p; --i) {
        sum += a[i];
        num++;
    }
    for(int i = p - 1; i >= 0; --i) {
        sum += a[i];
        num++;
        ans = max(ans, 1.0 * sum / num);
    }
    cout << fixed << setprecision(20);
    cout << ans << "\n";
}

signed main() {
    int t = 1;
    cin >> t;
    while(t--)
        solve();
    return 0;
}