SOLUTION: Could someone explain this to me because the book was no help. The random variable x has the following probability distribution: x 1 2 3 4

Algebra ->  Probability-and-statistics -> SOLUTION: Could someone explain this to me because the book was no help. The random variable x has the following probability distribution: x 1 2 3 4       Log On


   

Question 359027: Could someone explain this to me because the book was no help.

The random variable x has the following probability distribution:
x 1 2 3 4 5
___________________________________________________
P(x) 0.6 0.1 0.1 0.1 0.1
a.) Find the mean and standard deviation of x.
b). What is the probability that x is between mean - standard deviation and mean + standard deviation?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
mu is the mean.

mu=highlight%282%29
.
.
.
Calculate the variance first, then sigma.

VAR=%280.6%29%2B%280.1%29%2B4%280.1%29%2B9%280.1%29
VAR=2
sigma=sqrt%28VAR%29
sigma=sqrt%282%29
highlight%28sigma=1.414%29