中二數學...急!!20點. 頻數多邊形:)

[匿名]

2011-05-21 1:28 am

圖片參考：http://imgcld.yimg.com/8/n/HA07397813/o/701105200066013873441480.jpg

If the passing mark is set to be 64.5,how many students will fail? ___

If the passing mark is 64.5 ,find the percentage of students passed. ___

If 54% of the students are to fail,what should be the passing mark?___

If the passing mark is set to be 50.5,find the percentage of students passed the test. (中文:有幾多人合格)
_____________________

寫埋條識.and答案..thx:D

回答 (1)

wumantsun

2011-05-21 1:45 am

✔ 最佳答案

50個人
1.睇得唔係咁清楚，about 40 students
你係60.5-70.5之間的第四格畫條直線，遇到另一條線向橫睇就係答案
2.
(50-(第一題答案))/50*100%=20%
if 第一題答案=40
3.let x be the number of students that are fail.
x/50*100%=54%
x=27
打橫睇:
27果到畫橫線
遇到另一條線就打直落
大約係40.5
4.同第一,二條，都係對上去，有about36 students
(50-36)/50*100%=28%

方法就係咁，我可能睇唔清楚而唔岩
你要自己變通

2011-05-20 17:46:58 補充：
第一題應該係41-42人到
所以就應該係(50-(41or42))/50*100%

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