NO.PZ2015120604000092
问题如下：
The z-value of standard normal distribution are used to measure the distance between the mean and any other point, this distance is measured in unit of:
选项：
A.mode.
B.standard deviation.
C.variance.
解释：
B is correct
B is the definition of z-value.
請問題幹的意思，z value 用於衡量，均值到某個point的距離，那這個距離不應該是變量嗎？謝謝
