PP-DS-T2-136

[whoisallan]

DS2-136. 14393-!-item-!-187;#058&010357
x, 3, 1, 12, 8

If x is an integer, is the median of the 5 numbers shown greater than the average (arithmetic mean) of the 5 numbers?

(1) x > 6

(2) x is greater than the median of the 5 numbers.

ANS: E

請問如何解題?

[Huang Hsin-Yi]

這題你如果知道中位數與平均值的定義
在代入實際數字就可解題

[whoisallan]

thanks a lot!
我把式子列出來好了
1) 設X=20, 1,3,8,12,20
Median=8
Mean=44/5=8.8
Median<Mean, so weaken (1)
2)設X=20,
Median=8
Median<Mean, so weaken (2)
ANS:E

[Huang Hsin-Yi]

thanks a lot!
我想你的式子列一半
題目問 "是否"
我把式子列出來好了
1) 設X=20, 1,3,8,12,20
Median=8
Mean=44/5=8.8
Median<Mean,

設X=7, 1,3,7,8,12,
Median=7
Mean=31/5=6.2
Median>Mean, 所以無法回答是否,才weaken

以下同理
2)設X=20,
Median=8
Median<Mean, so weaken (2)
ANS:E