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

#define ll long long

int main() {
    int t;
    cin>>t;
    while(t--) {
        int n;
        cin>>n;
        vector<ll> v(n);
        int mididx = -1;
        for(int i=0; i<n; i++) {
            cin>>v[i];
            if(mididx==-1 && i>0 && v[i-1]<v[i]) {
                mididx = i-1;
            }
        }
        double leftmx = v[mididx-1];
        int leftmxidx = mididx-1;
        ll sum = leftmx;
        int idx = mididx-2;
        int leftcnt = 1;
        while(idx>=0) {
            sum += v[idx];
            leftcnt++;
            if(1.0*sum/leftcnt>leftmx) {
                leftmx = 1.0*sum/leftcnt;
                leftmxidx = idx;
            }
            idx--;
        }
        double rightmx = v[mididx+1];
        int rightmxidx = mididx+1;
        sum = rightmx;
        idx = mididx+2;
        int rightcnt = 1;
        while(idx<n) {
            sum += v[idx];
            rightcnt++;
            if(1.0*sum/rightcnt > rightmx) {
                rightmx = 1.0*sum/rightcnt;
                rightmxidx = idx;
            }
            idx++;
        }
        ll total = 0;
        for(int i=leftmxidx; i<=rightmxidx; i++) {
            total += v[i];
        }
        cout<<fixed<<setprecision(12)<<1.0*total/(rightmxidx-leftmxidx+1)<<endl;
    }
    return 0;
}