11. Which of the following procedures is always equivalent to adding 5 given numbers and then dividing the sum by 5 ?

I. Multiplying the 5 numbers and then finding the 5th root of the product.

II. Adding the 5 numbers, doubling the sum, and then moving the decimal point one place to the left.

III. Ordering the 5 numbers numerically and then selecting the middle number.

   (A) None

   (B) I only

   (C) II only

   (D) III only

   (E) I and III

第二个是5个数相加后乘以2再除以10（小数点向左挪一位）。相当于相加后除以5，与题干一致。所以选C。

多谢了！！！