“防溺水”是校园安全教育工作的重点之一.某校为确保学生安全,开展了“远离溺水·珍爱生命”的防溺水安全知识竞赛.现从该校七、八年级中各随机抽取10名学生的竞赛成绩(百分制)进行整理和分析(成绩得分用x表示,共分成四组:A.
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmn%3E80%3C%2Fmn%3E%3Cmo%3E%E2%A9%BD%3C%2Fmo%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%26lt%3B%3C%2Fmo%3E%3Cmn%3E85%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,B.
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmn%3E85%3C%2Fmn%3E%3Cmo%3E%E2%A9%BD%3C%2Fmo%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%26lt%3B%3C%2Fmo%3E%3Cmn%3E90%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,C.
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmn%3E90%3C%2Fmn%3E%3Cmo%3E%E2%A9%BD%3C%2Fmo%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%26lt%3B%3C%2Fmo%3E%3Cmn%3E95%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,D.
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmn%3E95%3C%2Fmn%3E%3Cmo%3E%E2%A9%BD%3C%2Fmo%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%E2%A9%BD%3C%2Fmo%3E%3Cmn%3E100%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
),下面给出了部分信息:
七年级10名学生的竞赛成绩是:96,84,97,85,96,96,96,84,90,96.
八年级10名学生的竞赛成绩在C组中的数据是:92,92,94,94.
七,八年级抽取的学生竞赛成绩统计表 年级 | 七年级 | 八年级 | 平均数 | 92 | 92 | 中位数 | 96 | m | 众数 | b | 98 | 方差 | 28.6 | 28 | | 八年级抽取的学生竞赛成绩扇形统计图 ![](http://tikupic.21cnjy.com/2022/06/17/93/e3/93e3bb9fdde1589f4688501676691997.png) |
根据以上信息,解答下列问题: