题目
设随机变量 X 服从正态分布 N(mu, sigma^2)，且 PX geq 1 = (1)/(2)，f(1) = 1，则（）A. mu = 1, sigma^2 = (1)/(sqrt(2pi))B. mu = 1, sigma^2 = (1)/(2pi)C. mu = 0, sigma^2 = 1D. mu = 1, sigma^2 = 1
设随机变量 $X$ 服从正态分布 $N(\mu, \sigma^2)$，且 $P\{X \geq 1\} = \frac{1}{2}$，$f(1) = 1$，则（）
A. $\mu = 1, \sigma^2 = \frac{1}{\sqrt{2\pi}}$
B. $\mu = 1, \sigma^2 = \frac{1}{2\pi}$
C. $\mu = 0, \sigma^2 = 1$
D. $\mu = 1, \sigma^2 = 1$
题目解答
答案
B. $\mu = 1, \sigma^2 = \frac{1}{2\pi}$