#include <bits/stdc++.h>

void solve() {
    int n;
    std::cin >> n;
    std::vector<int> a(n + 1);
    long double Max  = 0, Ans = 0;
    
    for (int i = 1; i <= n; i ++) {
        std::cin >> a[i];
        Max += a[i];
    }
    Ans = Max / n;
    std::cout << Ans << "\n";
}

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int T = 1;
    std::cin >> T;
    while (T --) {
        solve();
    }
}