作者ahold (Saatch aur Himmat.)
看板GMAT
標題Re: [計量] pp1 請教
時間Mon Sep 14 00:42:57 2009
原題有12個數據:
7.51、8.22、7.86、8.36、8.09、7.83
8.30、8.01、7.73、8.25、7.96、8.53
看有幾個在"1.5"個標準差的範圍內就好了
所以要在7.65~8.55的範圍內!
答案是11個沒錯吧?
※ 引述《a2515125 (Bobshih)》之銘言:
: A vending 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 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 12
: listed amounts are within 1.5 standard deviations of the mean?
: (A) Four
: (B) Six
: (C) Nine
: (D) Ten
: (E) Eleven
: 請問這題如何解?
: SD=0.3
: Mean=8.1
: 範圍7.8~8.4
: 然後呢~"~
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