#include <bits/stdc++.h>
using namespace std;
#define pi acos(-1)
#define xx first
#define yy second
#define endl "\n"
#define lowbit(x) x & (-x)
#define int long long
#define ull unsigned long long
#define pb push_back
typedef pair<int, int> PII;
typedef pair<double, double> PDD;
#define LF(x) fixed << setprecision(x)
#define Yshanqian ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
const int N = 1e6 + 10, M = 1010, inf = 0x3f3f3f3f, mod = 1e9 + 7, P = 13331;
const double eps = 1e-8;
int n;
int a[N];
void solve()
{
    int pos = 0, s = 0;
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i], s += a[i];
    for (int i = 2; i <= n - 1; i++)
    {
        if (a[i - 1] > a[i] && a[i + 1] > a[i])
        {
            pos = i;
            break;
        }
    }
    double ave = 1.0 * s / n;
    int pre = pos - 1;
    int suf = pos + 1;
    int l = 0, r = 0;
    for (int i = 1; i < pre; i++)
    {
        if (a[i] >= ave)
        {
            l = i;
            break;
        }
    }
    if (l == 0)
        l = pre;
    for (int i = n; i >= suf + 1; i--)
    {
        if (a[i] >= ave)
        {
            r = i;
            break;
        }
    }
    if (r == 0)
        r = suf;
    int cnt = 0;
    double ans = 0;
    for (int i = l; i <= r; i++)
    {
        ans += a[i];
        cnt++;
    }
    cout << LF(20);
    cout << max(1.0 * ans / cnt, ave) << endl;
}
signed main()
{
    Yshanqian;
    int T;
    T = 1;
    cin >> T;
    for (int cases = 1; cases <= T; ++cases)
    {
        // cout<<"Case #"<<cases<<": ";
        solve();
    }
    return 0;
}