#include <bits/stdc++.h>
using namespace std;
#define cin(v)        \
    for (auto &i : v) \
        cin >> i;
#define cout(v)       \
    for (auto &i : v) \
        cout << i << " ";
#define br cout << '\n';
#define ll long long
#define ull unsigned long long
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define MOD 1000000007
#define Time cerr << "Time Taken: " << (float)clock() / CLOCKS_PER_SEC << " Secs" \
                  << "\n";

void Warding()
{
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#endif
}

void solve()
{
    ll sum =0;
    int n; cin>>n;
    map<int,int> m;
    vector<int> v(n);
    for(int i=0; i<n; i++){
        cin>>v[i];
        sum += v[i];
        m[v[i]]++;
    }
    cout<<(m[sum/n] and (sum/n)*n==sum?"YES":"NO")<<'\n';
}

int main()
{
    Warding();
    int t = 1;
    cin >> t;
    while (t--)
    {
        solve();
    }
    Time
}