t = int(input())

for i in range(t):
    n = int(input())
    a = list(map(int, input().split()))
    x = max(a) - min(a)
    c = sum(a) / n
    vsum = 0
    for j in range(n):
        vsum += (a[j] - c) ** 2
    v = vsum / n
    print(x, f"{v:.3f}")