Question

亲,急求助一道概率论题

Answer 1

E(X)=0*1/2+1*1/4+2*1/8+3*1/8=1/4+1/4+3/8=0.875

D(X)=0^2*1/2+1^2*1/4+2^2*1/8+3^2*1/8-7/8*7/8=1/4+1/2+9/8-49/64=15/8-49/64=71/64

E(x²)=0^2*1/2+1^2*1/4+2^2*1/8+3^2*1/8=1/4+1/2+9/8=1.875

E(4X+1)=4*E(X)+1=4*7/8+1=4.5

D(4X+1)=4^2*D(X)=16*71/64=71/4=17.75