※ 引述《minimumi (米尼)》之铭言： : 121.(E) : 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 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? 他问有多少数是落在1.5倍的S.D.里 所以在 8.1+1.5*0.3=8.55 这个区间内 8.1-1.5*0.3=7.65 只有第一个7.51掉在这个区间外面 所以共有11个在那个区间内 : (A) Four : (B) Six : (C) Nine : (D) Ten : (E) Eleven : 想请问ㄧ下这题应该怎麽解 : 谢谢~ --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.120.80.19