求概率论题目
1个回答

1.

0.15*0.02+0.8*0.01+0.05*0.03=0.0125

2.

E(X)=-2/5-1/6+1/15+11/10

=(-24-10+4+66)/60

=36/60

=0.6

E(X^2)=4/5+1/6+1/15+99/30

=(48+10+4+198)/60

=26/6

=13/3

D(X)=E(X^2)-E(X)^2=13/3-0.36=11.92/3=3.97

E(3X+2)=3E(X)+2=3.8

3.

Z -1 0 1 2

P 1/4 1/3 1/6 1/4

X 0 1

P 1/4+1/6=5/12 7/12

Y -1 0 1

P 1/4+1/6=5/12 1/6+1/6=1/3 1/4

4.

1)Kx^3/3|(x 1)=1

K/3=1

K=3

2) ∫(0.1)3x^2 dx

=1-0.2^3

=0.992

3)F(x)=x^3 (0