Lily is designing a test to find out which of the two brands of washing power is better.
圖片參考：http://f20.yahoofs.com/hkblog/nxmf8DaGGRkSUBH9Xooahcnu60OH8mONxw--_1/blog/ap_20081012014132685.jpg.jpg?ib_____DPP.o5KW6
圖片參考：http://f20.yahoofs.com/hkblog/nxmf8DaGGRkSUBH9Xooahcnu60OH8mONxw--_1/blog/ap_20081012014353502.jpg.jpg?ib_____Dh2PwEDIp
She put stains on two pieces of cloth and washed them with the washing power as follows:
圖片參考：http://f20.yahoofs.com/hkblog/nxmf8DaGGRkSUBH9Xooahcnu60OH8mONxw--_1/blog/ap_20081012014626604.jpg.jpg?ib_____DZQmxsKyo
Diamond washing power: The machine is switched on for 10 mins.
圖片參考：http://f20.yahoofs.com/hkblog/nxmf8DaGGRkSUBH9Xooahcnu60OH8mONxw--_1/blog/ap_20081012014813289.jpg.jpg?ib_____D0Lj1Yn_b
Jade washing power: The machine is switched on for 5 mins.
Lily found that all the stains were removed with Diamond washing power but not with Jade washing power. She concluded that Diamond was better than Jade.
a) Explain why the test was not fair.
b)To carry out a fair test, what should you do?
S.1 science question [附圖]
2008-10-12 9:57 am
回答 (1)
2008-10-12 10:24 am
✔ 最佳答案
a) Explain why the test was not fair.The tests for Diamond and Jade were done under different conditions:
Diamond: 20L , 60oC, 10 minutes
Jade: 10L. 40oC, 5 minutes
Lily's conclusion is right for the two brands each was used under a different set of conditions ONLY.
b)To carry out a fair test, what should you do?
I would carry out the test, testing each brand under each of the two sets of conditions. Compare the results for each set of conditions. Draw conclusion from the results, specifying the washing conditions studied.
收錄日期: 2021-04-13 16:09:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081012000051KK00084