Let X∼N(0,1)X \sim N(0, 1)X∼N(0,1). Find the expected value of XXX given that X>0X > 0X>0.
2π\sqrt{\frac{2}{\pi}}π2
12π\frac{1}{\sqrt{2\pi}}2π1
π2\sqrt{\frac{\pi}{2}}2π
111