#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int inf=1e9+7;
const int N=5e2+5;
const int M=N*N;
int T,n,m,p[N];
struct vec{
	int x;
	int y;
	vec(int a=0,int b=0):x(a),y(b){}
}a[N];
ll dot(const vec &a,const vec &b)
{
	return 1ll*a.x*b.x+1ll*a.y*b.y;
}
ll cross(const vec &a,const vec &b)
{
	return 1ll*a.x*b.y-1ll*a.y*b.x;
}
ll dis2(const vec &a)
{
	return dot(a,a);
}
vec operator - (const vec &a,const vec &b)
{
	return vec(a.x-b.x,a.y-b.y);
}
int find(const vec &a)
{
	if(!a.y)return a.x>0?0:2;
	else return a.y>0?1:3;
}
bool operator < (const vec &a,const vec &b)
{
	int x=find(a);
	int y=find(b);
	return x^y?x<y:cross(a,b)>0;
}
struct zj{
	vec ang;
	int u,v;
	ll x,y;
	bool operator < (const zj &a)const{
		return ang<a.ang;
	}
}b[M];
double f[N];
bool check(int s,double k)
{
	fill(f+1,f+1+n,-inf);
	f[s]=0;
	for(int i=1;i<=m;i++)
	{
		f[b[i].v]=max(f[b[i].v],f[b[i].u]+b[i].x-k*b[i].y);
	}
	return f[s]>0;
}
mt19937 rnd(time(0)); 
const double eps=1e-10;
void solve()
{
	scanf("%d",&n);
	m=0;
	for(int i=1;i<=n;i++)scanf("%d%d",&a[i].x,&a[i].y);
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)
		{
			if(i==j)continue;
			b[++m]={a[j]-a[i],i,j,cross(a[i],a[j]),dis2(a[i]-a[j])};
		}
	}
	sort(b+1,b+1+m);
	iota(p,p+1+n,0);
	shuffle(p+1,p+1+n,rnd);
	double ans=0;
	for(int x=1,i;i=p[x],x<=n;x++)
	{
		if(!check(i,ans))continue;
		double l=ans,r=1e8,mid;
		while((r-l)/max(1.0,l)>eps)
		{
			mid=(l+r)/2;
			if(check(i,mid))l=mid;
			else r=mid;
		}
		ans=l;
	}
	printf("%.10lf\n",ans/2);
}
int main()
{
	int T;
	scanf("%d",&T);
	while(T--)solve();
	return 0;
}