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

void solve() {
    int n;
    scanf("%d", &n);
    vector<long long> a(n + 2); 
    a[0] = LLONG_MAX;
    a[n + 1] = LLONG_MAX;

    for (int i = 1; i <= n; i++) {
        scanf("%lld", &a[i]);
    }

    // 找到 V 图的最低点（即转折点）
    int tip = -1;
    for (int i = 2; i <= n - 1; i++) {
        if (a[i - 1] > a[i] && a[i] < a[i + 1]) {
            tip = i;
            break;
        }
    }

    if (tip == -1) {
        // 如果没有找到转折点，整个序列可能是单调的，但根据题目保证，这种情况不会发生
        tip = 1;
    }

    double maxAvg = a[tip]; // 初始化最大平均值为 tip 位置的元素值
    long long sum = a[tip];
    int len = 1;

    // 从 tip 开始，向右扩展
    int r = tip;
    while (r + 1 <= n && a[r + 1] > a[r]) {
        r++;
        sum += a[r];
        len++;
        double avg = (double)sum / len;
        if (avg > maxAvg) {
            maxAvg = avg;
        }
    }

    // 重置 sum 和 len
    sum = a[tip];
    len = 1;

    // 从 tip 开始，向左扩展
    int l = tip;
    while (l - 1 >= 1 && a[l - 1] > a[l]) {
        l--;
        sum += a[l];
        len++;
        double avg = (double)sum / len;
        if (avg > maxAvg) {
            maxAvg = avg;
        }
    }

    // 同时向两侧扩展
    sum = a[tip];
    len = 1;
    l = tip;
    r = tip;
    while (true) {
        bool moved = false;

        // 尝试向右扩展
        if (r + 1 <= n && a[r + 1] > a[r]) {
            r++;
            sum += a[r];
            len++;
            double avg = (double)sum / len;
            if (avg > maxAvg) {
                maxAvg = avg;
            }
            moved = true;
        }

        // 尝试向左扩展
        if (l - 1 >= 1 && a[l - 1] > a[l]) {
            l--;
            sum += a[l];
            len++;
            double avg = (double)sum / len;
            if (avg > maxAvg) {
                maxAvg = avg;
            }
            moved = true;
        }

        if (!moved) {
            break;
        }
    }

    // 考虑整个序列
    sum = 0;
    for (int i = 1; i <= n; i++) {
        sum += a[i];
    }
    double avg = (double)sum / n;
    if (avg > maxAvg) {
        maxAvg = avg;
    }

    // 输出结果，保证精度
    printf("%.10f\n", maxAvg);
}

int main() {
    int t;
    scanf("%d", &t);
    while (t--) solve();
    return 0;
}