#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
#define ll long long
#define fr first
#define sc second
#define pb push_back
#define MAX ((ll)(1e18 + 100))
#define MX ((ll)(1e6 + 100))
#define ARRS ((ll)(1e6 + 100))
#define MOD ((ll)(998244353))
#define PI ((double)3.141592653)
#define EP ((double)(1e-9))
#define LG 21

ll a[ARRS];

int main() {

  ios::sync_with_stdio(0);
  ll q;
  cin>>q;
  while(q--){
    ll n;
    cin>>n;
    double s=0;
    double ans=0;
    ll c=0;
    for(int i=0; i<n; i++){
      cin>>a[i];
    }
    ll C;
    for(int i=1; i<n-1; i++){
      if(a[i-1]>a[i]&&a[i]<a[i+1])C=i;
    }

    s=0;c=0;
    for(int i=0; i<n; i++){
      c++;
      s+=a[i];
      if(i>=C)
        ans=max(ans, s/c);
    }
    s=0;c=0;
    for(int i=n-1; i>=0; i--){
      c++;
      s+=a[i];
      if(i<=C)
        ans=max(ans, s/c);
    }
    printf("%.12f\n", ans);
  }
  return 0;
}