lijiahui0422,看你在,想问你个问题,以前曾经问过,但不知道怎么查, 我查的时候只有自己的发言,可看不到别人的解答,怎么回事. 问题如下:
3.7.51 8.22 7.86 8.36 8.09 7.83 8.30 8.01 7.73 8.25 7.96 8.53 A vending machine is designed to a dispense 8 ounces of coffee into a cup. After a test that recorded the number of ounces of coffee in each of 1,000 cups dispensed by the vending machine. The 12 listed amounts, in ounces, were selected from the data. If the 1,000 recorded amounts have a mean of 8.1 ounces and a standard deviation of 0.3 ounce, how many of the listed amounts are within 1.5 standard deviation of the mean? Key: 11. how to solve this question? 对最后一句话的理解不是很有把握?
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