t=int(input())

for i in range(t):
    n=int(input())
    ls=list(map(int,input().split()))
    avg=sum(ls)/len(ls)
    fangcha=0
    fangcha_ls=[]
    for a in range(len(ls)):
        fangcha_ls.append((ls[a]-avg)**2)
        f=sum(fangcha_ls)/len(ls)
    print(max(ls)-min(ls),f'{f:.3f}')