prep的一道数学题，请大家帮忙看一下

chensong211 · 发表于 2012-3-22 00:45:27

A wending machine is designed to dispense 8 ounces of coffee into a cup. After a test that recorded the number of ounces of coffee in each of 1000 cups dispensed by the vending machine, the 12 listed amounts, in ounces, were selected from the data. If the 1000 recorded amounts have a mean of 8.1 ounces and a standard deviation of 0.3 ounce, how many of the 12 listed amounts are within 1.5 standard deviations of mean?

数据：

7.51 8.22 7.86 8.36

8.09 7.83 8.30 8.01

7.738.25 7.968.53

正确答案是11 这道题我不会做。请大家帮忙看一下，谢谢

chensong211 · 发表于 2012-3-22 10:19:18

自己顶

prep的一道数学题，请大家帮忙看一下

所属分类: GMAT考试

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