1.某位老師想了解班上60名同學中，約有多少比率在國中前即談過戀愛，於是他設計了 A、B兩份問卷(其中A卷40張，B卷20張)以及不記答案卷60張隨機發給班上同學(同學 不是拿到A卷就是B卷.至於A、B卷皆不回收，但答案卷要回收)，其中A卷的問題是「 我曾經在國中以前談過戀愛」，因此拿到A卷的同學若國中前談過戀愛就要在答案卷 上劃O，若不曾談過戀愛則劃X；反之，B卷的問題是「我不曾在國中以前談過戀愛」， 因此拿到B卷的同學若國中前談過戀愛，就要在答案卷上劃X，若不曾談過戀愛，則劃O， 如此設計，不論某位學生回答的結果是O或X，老師都無法得知該生在國中以前是否談過 戀愛，但卻可大致了解全班狀況。答案卷經回收後，老師發現60張答案中友25張劃O， 35張劃X。請求出在本班同學中，約有多少比率的同學曾在國中以前談過戀愛? 2.A city has professional basketball team playing at home and professional hockey team playing away on the same night. According to probabilities for professional sports published in Chance (Fall, 1992), a professional basketball team has a 0.641 probability of winning a home game, and a profess ional hockey team has a 0.462 probability of winning an away game. Historically,when both teams play on the same night, the chance that the next morning's leading sports story will be about the basketball game is 60% and the chance that it will be about the hockey game is 40%. Suppose that on the morning after these games the newspapers' leading sports story begins with headline “We Win!!” What is the probability that the story is about the basketball team? 先謝謝大家幫忙解惑喔 --

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