[解題] 高二數學統計
1.年級:高二
2.科目:數學
3.章節:統計
4.題目:213班共42人,第二次期中考試的算術平均數為61分,為標準差為11,其中甲、乙
二位同學的原成績分別為x,y(x>y),因電腦失誤,使甲、乙二位同學的成績全變
成0分;後來全班成績經重新計算後,算術平均數與標準差均不變,請問:甲原成
績為幾分?
5.想法:說實在的,我看到題目時根本覺得題目出錯了,怎麼可能本來兩個0分的加了分數
之後算術平均數可以不變。答案是72分,請教各位高手。
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◆ From: 122.120.11.1
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06/11 00:12, , 1F
06/11 00:12, 1F
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06/11 00:15, , 2F
06/11 00:15, 2F
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06/11 00:23, , 3F
06/11 00:23, 3F
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06/11 00:24, , 4F
06/11 00:24, 4F
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06/11 00:24, , 5F
06/11 00:24, 5F
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06/11 00:26, , 6F
06/11 00:26, 6F
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06/11 00:27, , 7F
06/11 00:27, 7F
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06/11 00:33, , 8F
06/11 00:33, 8F
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06/11 00:41, , 9F
06/11 00:41, 9F
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06/11 00:58, , 10F
06/11 00:58, 10F
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06/11 01:59, , 11F
06/11 01:59, 11F
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06/11 02:03, , 12F
06/11 02:03, 12F