1 #include<stdio.h>
 2 int main()
 3 {
 4     int i,j,s,b,a;
 5     float t;
 6     s=0;
 7     for (i=1;i<=5;i++)
 8     {
 9         while(scanf("%d",&a)==1)
10         {
11                 for (j=1;j<=a;j++)
12                 {
13                     scanf("%d",&b);
14                     s=s+b;
15                 }
16                 t=s/(a/1.0);
17                 s=0;
18                 printf("%.3f\n",t);
19         }
20     }
21 }