...已知他们每一次投篮投中的概率均为 ,且各次投篮的结果互不影响.甲同...
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发布时间：2024-10-22 07:59
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时间：2024-11-17 07:21
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的数学期望 ．
试题分析：（1）这属于独立重复试验，至少投中4次，分恰好投中4次和恰好投中5次两种情况，即 ；（2）投篮次数 分别等于 ，例如 时前3次未投中第4次投中，概率为 ，依次计算，可得到分布列，再根据公式计算出数学期望.
试题解析：（1）设甲同学在5次投篮中，有 次投中，“至少有4次投中”的概率为 ，则
2分
= = ． 4分
（2）由题意 ．
， ， ， ，
．
的分布表为
1
2
3
4
已赞过已踩过你对这个回答的评价是？评论收起 ._1uevpeq{zoom:1;background-color:#fff;border:0;margin-bottom:10px;padding:30px 0 20px 42px;position:relative}._1uevpeq.ec-1841{padding:20px 0}._1uevpeq.ec-2246{padding:20px 0 10px}.ec-1841 .y7we4hu{font-size:16px;margin-bottom:-5px}.y7we4hu{color:#7a8f9a;height:25px;line-height:25px;overflow:hidden;position:relative}.y7we4hu h2{margin:0;padding:0}.y7we4hu:after{clear:both;content:" ";display:block;height:0;visibility:hidden}a.tycfu7u{color:#666;float:right;font-size:12px;margin-left:8px;text-decoration:none}.hhhv6ex{color:#666;font-size:13px;line-height:normal;line-height:20px;margin-top:10px}.vnsdjzp{margin-top:15px;position:relative}.vnsdjzp h3{font-weight:400;padding:0}.vnsdjzp a{text-decoration:none}.vnsdjzp em{color:#d81419;font-style:normal}.ec-2246 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热心网友
时间：2024-11-17 07:23
1
2
3
4
5
的数学期望 ．
试题分析：（1）这属于独立重复试验，至少投中4次，分恰好投中4次和恰好投中5次两种情况，即 ；（2）投篮次数 分别等于 ，例如 时前3次未投中第4次投中，概率为 ，依次计算，可得到分布列，再根据公式计算出数学期望.
试题解析：（1）设甲同学在5次投篮中，有 次投中，“至少有4次投中”的概率为 ，则
2分
= = ． 4分
（2）由题意 ．
， ， ， ，
．
的分布表为
1
2
3
4
已赞过已踩过你对这个回答的评价是？评论收起 ._1uevpeq{zoom:1;background-color:#fff;border:0;margin-bottom:10px;padding:30px 0 20px 42px;position:relative}._1uevpeq.ec-1841{padding:20px 0}._1uevpeq.ec-2246{padding:20px 0 10px}.ec-1841 .y7we4hu{font-size:16px;margin-bottom:-5px}.y7we4hu{color:#7a8f9a;height:25px;line-height:25px;overflow:hidden;position:relative}.y7we4hu h2{margin:0;padding:0}.y7we4hu:after{clear:both;content:" ";display:block;height:0;visibility:hidden}a.tycfu7u{color:#666;float:right;font-size:12px;margin-left:8px;text-decoration:none}.hhhv6ex{color:#666;font-size:13px;line-height:normal;line-height:20px;margin-top:10px}.vnsdjzp{margin-top:15px;position:relative}.vnsdjzp h3{font-weight:400;padding:0}.vnsdjzp a{text-decoration:none}.vnsdjzp em{color:#d81419;font-style:normal}.ec-2246 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