以下是引用piipii在2006-11-14 19:13:00的发言:94题:今天作prep第一题碰到跟这个题目类似的一个题 给了8个数字 9.4 9.9 9.9 9.9 10.0 10.2 10.2 10.5 The mean and the standard deviation of the 8 numbers shown are 10.0 and 0.3, repetively. What percent of the 8 numbers are with 1standard deviation of the mean? A 90% B 85% C 80% D 75% E 70% 如果是10+1or10-1的话,那这个题目答案应该是7/8 (87.5%) 按照prep给的答案,应该是认为9.4和10.5都不符合with 1 SD 大家认为那? 明天考试盼答案 1st std.所以the value is between (10-0.3) and (10+0.3) 符合條件有6個 6/8=75%
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