Question

What is the expected value of X?

6.2


6.05


5.95


5.6




X 3 4 5 7 9
P 0.2 0.1 0.25 0.05 0.4

Answer 1

6.2

Explanation:

Multiply each X by its corresponding probability P, then add up them up.

E[X] = 3•0.2 + 4•0.1 + 5•0.25 + 7•0.05 + 9•0.4

⇒ E[X] = 6.2