某地7岁健康男童身高(cm)抽样调查资料表11-23。请采用拟合优度的X2检验,推断该资料是否服从正态分布?
正确答案:先计算均数和标准差
用表中的组段中组中值作为原始数据进行计算,得到
,
由于样本量较大,视为总体参数估计值,对组段的上下限作标准正态分布变换
,并计算各个组段的概率和期望值,得到结果如下
![](https://img.274949.com/Images/2020-04/02/w8vftc5p.jpg)
![](https://img.274949.com/Images/2020-04/02/e4c591nv.jpg)
用表中的组段中组中值作为原始数据进行计算,得到
![](https://img.274949.com/Images/2020-04/02/pds1bo3i.jpg)
![](https://img.274949.com/Images/2020-04/02/ttcmhtwx.jpg)
![](https://img.274949.com/Images/2020-04/02/orjvusdb.jpg)
![](https://img.274949.com/Images/2020-04/02/w8vftc5p.jpg)
![](https://img.274949.com/Images/2020-04/02/e4c591nv.jpg)
答案解析:有
![](/editor/images/201705/qrcode_for_gh_573e2a458573_258.jpg)
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某地7岁健康男童身高(cm)抽样调查资料表11-23。请采用拟合优度的X2检验,推断该资料是否服从正态分布?
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