1 .
年
月
日,我国第
颗北斗导航卫星发射成功.为提升卫星健康运转的管理水平,西安卫星测控中心组织青年科技人员进行卫星监测技能竞赛,成绩分为“优秀”、“良好”、“待提高”三个等级.现有甲、乙、丙、丁四人参赛,已知这四人获得“优秀”的概率分别为
、
、
、
,且四人是否获得“优秀”相互独立,则至少有
人获得“优秀”的概率为( )
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f592748753dbbbd747a14a94a2dea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92128c6c226ce688bc160fb86854f2fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
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