Given themarks of 5 mathematics tests of a student are: 20, 20, 75, 80, 90. What is the bestrepresentation of this set of data?The model answer is mean, but I don't understand.Please explain. Thanks.
mean is the best?
2014-01-22 3:15 am
回答 (3)
2014-01-22 4:18 pm
✔ 最佳答案
其實一般來說 mean is the best，只有一些極端的情況會選擇 median or mode。舉個例子：20, 20, 20, 20, 20, 2000，如用 mean = 350 來表示大部分的數據是不妥的，這情況會用 median 或 mode = 20。以你這個例子說明，我反而會選擇用 median = 75 來表達，原因有二，一則大部分數據都接近 75，二則容易計算。
參考: knowledge
2014-01-23 11:17 pm
There are 6 situations :
1. Take all data into consideration - Mean
2. Influenced by extreme values - Mean
3. Easy to compute - Median or Mode
4. Must be one of the datum - Mode
5. Uniqueness - Mean or Median
6. May not exist in some situations - Mode
2014-01-23 15:19:00 補充：
For this case, the best choice is Mean.
1. Take all data into consideration - Mean
2. Influenced by extreme values - Mean
3. Easy to compute - Median or Mode
4. Must be one of the datum - Mode
5. Uniqueness - Mean or Median
6. May not exist in some situations - Mode
2014-01-23 15:19:00 補充：
For this case, the best choice is Mean.
2014-01-22 3:23 am
呢ｄ題目係無特定答案的，只要你 argue 到就得～
另一個人答你 median，如果解釋得好一樣得～
（不過一般黎講如果個 distribution 係 far from symmetric 的話，median可能會比較 representative，但我個人覺得呢個所謂 best representative 係唔應該有獨特答案的，除非題目講明要求，咩為之 best representative）
2014-01-22 12:22:05 補充：
50418129 就講得岩啦！
所以同學都問得好正確～
佢問都係可能心裏面覺得有ｄ唔妥當，點解答案話用 mean 呢～咁。
另一個人答你 median，如果解釋得好一樣得～
（不過一般黎講如果個 distribution 係 far from symmetric 的話，median可能會比較 representative，但我個人覺得呢個所謂 best representative 係唔應該有獨特答案的，除非題目講明要求，咩為之 best representative）
2014-01-22 12:22:05 補充：
50418129 就講得岩啦！
所以同學都問得好正確～
佢問都係可能心裏面覺得有ｄ唔妥當，點解答案話用 mean 呢～咁。
收錄日期: 2021-04-28 14:41:01
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140121000051KK00155