[讨论]数学GWD-4-17

wanders

这题一点思路没有，请指教。谢谢

The number of defects in the first five cars to come through a new production line are 9, 7, 10, 4, and 6, respectively. If the sixth car through the production line has either 3, 7, or 12 defects, for which of theses values does the mean number of defects per car for the first six cars equal the median?

I. 3

II. 7

III. 12

A. I only

B. II only

C. III only

D. I and III only

E. I, II, and III

sammen

答案是D。题目问的是哪个数可以使中位数和平均数一样，中位数就是排序后中间的数字，这里象数是偶数所以是中间2个数的平均。