Question

Choose the correct option from the given alternative:

Find expected value of and variance of X for the following p.m.f.

X	-2	-1	0	1	2
P(x)	0.3	0.3	0.1	0.05	0.25

Options

• 0·85

• – 0·35

• 0·15

• – 0·15

Answer 1

Explanation:

E(x) = ∑x_ip_i

E(x) = (-2)(0.3) + (-1)(0.3) + (0)(0.1) + (1)(0.05) + (2)(0.25)

= -0.6 - 0.3 + 0 + 0.05 + 0.5

= -0.35