Question

Consider the probability distribution shown below.

x	0	1	2
P(x)	0.65	0.30	0.05

Compute the expected value of the distribution.


Compute the standard deviation of the distribution. (Round your answer to four decimal places.)

Answer 1

Solution:

x	P(x)	x * P(x)	x2 * P(x)
0	0.65	0	0
1	0.3	0.3	0.3
2	0.05	0.1	0.2
Sum	1	0.4	0.5

Mean = X * P(X)

= 0.4

Standard deviation =

=X 2 * P(X) - 2

=  0.5 - (0.4)2 = 0.34

Standard deviation = = 0.5831