#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include <stack>

using i64 = long long;

void solve()
{
#define tests
    int n, cnt = 0, dt;
    double ans = 0, sum = 0, pos = 1;
    std::cin >> n;
    std::vector <int> nums(n + 1);
    for(int i = 1 ; i <= n ; i++){
        std::cin >> nums[i];
        if(nums[pos] > nums[i])
            pos = i;
    }
    sum += nums[pos];
    cnt++;
    ans = sum / cnt;
    int l = pos - 1, r = pos + 1;
    while(l >= 1 || r <= n){
        if(l >= 1 && r <= n){
            dt = 0;
            while(l - dt >= 1 && r + dt <= n && nums[l - dt] == nums[r + dt])
                dt++;
            if(l - dt >= 1 && r + dt <= n && nums[l - dt] > nums[r + dt]){
                sum += nums[l];
                l--;
                cnt++;
            }else{
                sum += nums[r];
                r++;
                cnt++;
            }
            //ans = std::max(ans, sum / cnt);
        }else{
            if(l >= 1){
                sum += nums[l];
                l--;
                cnt++;
            }
            if(r <= n){
                sum += nums[r];
                r++;
                cnt++;
            }
        }
        ans = std::max(ans, sum / cnt);
    }
    printf("%0.20lf\n",ans);
}
 
signed main()
{
    std::cin.tie(nullptr)->sync_with_stdio(false);
    int _{1};
#ifdef tests
    std::cin >> _;
#endif
    while(_--) solve();
    return 0;
}