hdu 5003 Osu!

#include<iostream>
#include<cmath>
#include<queue>
#include<vector>
#include<algorithm>
#include<string.h>
#include<cstdio>

using namespace std;

#define ll long long

double a[510];

int main(){
    int t;
    cin>>t;
    while(t--){
        int n;
        cin>>n;
        double ans=0.0;
        for(int i=1;i<=n;i++){
            cin>>a[i];
        }
        sort(a+1,a+n+1);
        for(int i=n;i>0;i--){
            ans+=pow(0.95,n-i)*a[i];
        }
        printf("%.8lf\n",ans);
    }
    return 0;
}