快考了 求助50题中的Q25~~~~~~~~~~~~~

miffyflysky

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*Twenty-five adults reported the amount of time each spent exercising during a particular week. The results are summarized in the graph as follows: 5 respondents reported exercising for less than 1 hour, 3 respondents reported exercising for at least 1 hour but less than 2, and so on.

Based on the information above, use the drop-down menus to most accurately complete the following statements.

25A. The least possible value for the mean of the numbers of hours of exerdse reported for the weeks is Select...

解题方法：<v:shape style="WIDTH: 227.25pt; HEIGHT: 31.5pt" id=_x0000_i1026 equationxml='&#13;&#10;&#13;&#10;1250+31rlPr><+2rlPr>2+4><3+44+55+1

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8+1锛?/m:t>10锛?/m:t>5+3+2+4+4+5+1+1' type="#_x0000_t75"> =<v:shape style="WIDTH: 11.25pt; HEIGHT: 31.5pt" id=_x0000_i1028 equationxml='&#13;&#10;&#13;&#10;127825' type="#_x0000_t75"> =3.12  

答案：3.12

不太懂咦。。。。。。。

baiyustephanie

问题问的是最小的平均值，所以就将每一个阶段的工作小时数取到最低。
5*0+3*1+2*2+4*3+4*4+5*5+1*8+1*10
再除以25

ywxkdxh

明白了~O(∩_∩)O~

WindyMM

刹那间，我的理解least possible是最不可能的。。。。哎玛。。。我这什么思维。。。感谢纠正