import sys

n = int(input())

for i in range(n):
    l = int(input())
    a = list(map(int,input().strip().split()))
    maxa = max(a)
    mina = min(a)
    cha = maxa - mina
    avg = sum(a)/l
    fangcha = sum([(x-avg)**2 for x in a])/l
    print(cha,"%.3f"%fangcha)