( 1)P=0.4*0.4*0.4=0.064

I forgot how to type that symbol. . . The current x represents)

Question: X can take 2, 3 and 4.

p(2)= 1 * 0.4 * 0.4 = 0. 16

P(3)=2*0.4*0.6=0.48

P(4)= 1*0.6*0.6=0.36

Distribution list

X 2 3 4

P 0. 16 0.48 0.36

(The picture above is an online distribution list. )

hope

EX = 2 * 0. 16+3 * 0.48+4 * 0.36 = 0.32+ 1.44+ 1.44 = 3.2

Remember to change the x above back to that symbol ~! )