length_list=[]
exam_papers=int(input())
matrix=[[] for _ in range(exam_papers)]
result=[[] for _ in range(exam_papers)]
for i in range(exam_papers):
length_list=list(input())
matrix[i]=list(map(int,input().split()))
for i in range(exam_papers):
jicha=max(matrix[i])-min(matrix[i])
mean=sum(matrix[i])/(len(matrix[i]))
variance=0
for item in matrix[i]:
variance+=(item-mean)**2/len(matrix[i])
result[i].append(jicha)
result[i].append(variance)
for i in result:
for j in range(2):
if j == 0:
print(i[j],end=" ")
else:
print(f"{i[j]:.3f}")