Question

Question 2
• The number of electrical outages in a city varies from day to day. Assume that
the number of electrical outages («) in the city has the following probability
distribution
f)
0
0.8
0.15
2
3
0.01
و مرا به دو
A) The mean for the number of electrical outages is
B) The standard deviation for the number of electrical outages is

Answer 1

Answer:

The answer is below

Explanation:

Probability distribution are statistical function that shows all the possible outcomes of a random variable within a given range of values.

a) The mean ($\bar x$) of a probability distribution of a discrete random variable is:

$\bar x=\Sigma\ [xP(x)]$ = (0 * 0.8) + (1 * 0.15) + (2 * 0.04) + (3 * 0.01) = 0.26

b) The standard deviation (σ) of a probability distribution of a discrete random variable is:

$\sigma=\sqrt{ \Sigma\ [(x-\bar x)^2*P(x)]}\\\\\sigma=\sqrt{(0-0.26)^2*0.8+(1-0.26)^2*0.15+(2-0.26)^2*0.04+(3-0.26)^2*0.01} \\\\\sigma=0.577$