※ 引述《betterman720 (betterman)》之铭言： : 以PP2-CR-40举例好了 : 40. (32847-!-item-!-188;#058&007552) : A recent report determined that although only three percent of drivers on : Maryland highways equipped their vehicles with radar detectors, thirty-three : percent of all vehicles ticketed for exceeding the speed limit were equipped : with them. Clearly, drivers who equip their vehicles with radar detectors : are more likely to exceed the speed limit regularly than are drivers who : do not. : The conclusion drawn above depends on which of the following assumptions? : (A) Drivers who equip their vehicles with radar detectors are less likely to be : ticketed for exceeding the speed limit than are drivers who do not. : (B) Drivers who are ticketed for exceeding the speed limit are more likely to : exceed the speed limit regularly than are drivers who are not ticketed. : (C) The number of vehicles that were ticketed for exceeding the speed limit : was greater than the number of vehicles that were equipped with radar : detectors. : (D) Many of the vehicles that were ticketed for exceeding the speed limit : were ticketed more than once in the time period covered by the report. : (E) Drivers on Maryland highways exceeded the speed limit more often than : did drivers on other state highways not covered in the report. : 答案是(B) : 想很久还是不知道为什麽 : 有牛人愿意解惑吗? : 小弟先谢过了^^ 题目： 该州3%的人装有雷达探测器 该州被开超速罚单的人33%装有雷达探测器 作者结论： 装有雷达探测器的人比没装的人较会超速 前提是： 被开超速罚单的人都是因为常超速才会被开单， 如果是偶尔才超速却常被开单的话（＝被开单的都是很少超速的人）， 整篇的立足点就消失了。 所以答案是B --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 75.86.183.56 虽然只有3%的人装雷达探测器，但是被开单的人中却有33%的人都装有雷达探测器， 作者的结论是装有雷达探测器的人较会超速。 装雷达探测器的人->较会超速->所以常被开单 所以要成立作者的结论的前提是因为被开单的人都是因为常超速才被开单， 而不是常被开单的人都是因为偶尔超速却"倒楣"被开单。 这样解释有比较清楚吗？@@ 若还是不清楚我明天睡醒再想方法解释，今天算太多数学，头昏昏脑顿顿的~"~ ※ 编辑: aaaaaakoyasu 来自: 65.29.188.149 (10/26 14:54)