import numpy as np
import matplotlib.pyplot as plt
c=int(input())
s=list()
for i in range(c):
    s.append(np.array(list(map(int,input().split()[1:]))))
for i in range(c):
    print('%.3f%%'%(round(np.where(s[i]>s[i].mean(),1,0).sum()*100/len(s[i]),3)))
    plt.hist(s[i], bins=100)
    plt.show()