SOLUTION: The table below shows the probability distribution of the random variable X. a. Find the mean of the random variable. b. Obtain the standard deviation sigma of the random variab

Algebra ->  Probability-and-statistics -> SOLUTION: The table below shows the probability distribution of the random variable X. a. Find the mean of the random variable. b. Obtain the standard deviation sigma of the random variab      Log On


   

Question 1126898: The table below shows the probability distribution of the random variable X.
a. Find the mean of the random variable.
b. Obtain the standard deviation sigma of the random variable.
x P(X=x)
1 0.1
2 0.4
3 0.5
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
mean or expected value is sum of x*p(x)
that is 0.1+0.8+1.5 or 2.4
sd
first, [x-(E(X))^2 * p(x)]
-1.4^2*0.1=.196
-0.4^2*0.4=0.064
0.6^2*0.5=0.18
sum is 0.44
Take the square root = 0.66 is sd