standardized normal distribution

例句：

1. 1. The data isnormally distributed around the mean.
   数据围绕均值呈正态分布。
2. 2. The standard normal distributionis used to calculate the expected value ofa random variable.
   标准正态分布用于计算随机变量的期望值。
3. 3. Thestandardized normal distribution isoften used in statistical analysis.
   标准化正态分布常用于统计分析。