[問題]天山 03-14

[Janet]

Yesterday each of the 35 members of a certain task force spent some time working on
project P. The graph shows the number of hours and the number of members who spent
that number of hours working on project P yesterday. What was the median number of
hours that the members of the task force spent working on project P yesterday?

A. 2
B. 3
C. 4
D. 5
E. 6

ans:e

可能是我很久沒複習了,共35人,求median,應該在17.5的地方,

但是17.5的地方又剛好是5與6的交界,請問各位如何選擇呢?

[fiona]

中位數應該是18
到5的地方剛好是第17人
所以是6囉

[Janet]

謝謝....果然是太久沒複習.頭腦打劫...^^

[chris8888]

這一題問hours, 應該要用hours才可以完全確認吧.

1*9 + 2*4 + 3 * 1 + 4 * 2 + 5 * 1 + 6 * 8 + 7 * 10 = 151, 中位數應該要出現在75.5的地方

累加
9 => 17 => 20 => 28 => 33 => 81 <== 出來了, 就是6 hours的位置