请教一道模拟题

jurancc · 发表于 2012-9-17 10:43:35

for a certain examination, a score of 58 was 2 standard deviation below the mean, a score of 98 was 3 standard deviation above the mean,what was the mean score of the exam.
A74 B 76 C78 D80 E82

题目看不懂，求

stlibai · 发表于 2012-9-17 12:25:35

晕，没看清楚lz求什么，lz你是求安慰啊求翻译阿还是求解答阿

stlibai · 发表于 2012-9-17 12:24:57

58分低于均分两个标准差,98分高于均分三个标准差

58+2x=98-3x

x=8

均分=74

请教一道模拟题

所属分类: GMAT考试

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