NO.PZ2019040801000017
问题如下:
The probability that a standard normally distributed random variable will be less than one standard deviation above its mean is:
选项:
A.
0.6827.
B.
0.8413.
C.
0.3173.
D.
0.1587.
解释:
B is correct
考点:正态分布查表
解析:题目问,对于正态分布,随机变量小于均值以上一倍标准差的概率是多少?查表得到P(X<1) = 0.8413
标准正态分布中距离均值1倍标准差对应概率是68%,小于这概率不就是答案吗?