Question

The table below shows the probability distribution of a random variable X. Х P(X) -10 0.11 -9 0.13 -8 0.18 -7 0.02 -6 0.16 -5 0.13 -4 0.27 What is the mean of the probability distribution? Write your answer as a decimal.

Answer 1

x p(x) x.p(x)

-10 0.11 -1.1

-9 0.13 -1.17

-8 0.18 -1.44

-7 0.02 -0.14

-6 0.16 -0.96

-5 0.13 -0.65

-4 0.27 -1.08

Mean = sum of x.p(x)

mean = -1.1 + (-1.17) + (-1.44) + (-0.14) + (-0.96) + (-0.65) + (-1.08)

= - 1.1 - 1.17- 1.44 - 0.14 - 0.96 - 0.65 - 1.08

mean = -6.54