Question

Consider the following data:

x	−4	−3	−2	−1	0
P(X=x)P(X=x)	0.3	0.1	0.1	0.2	0.3

Copy Data

Step 2 of 5 :

Find the variance. Round your answer to one decimal place.

Answer 1

	Input Field	Input Field
	X	P(X = x)	X*P(X =x)	X*X*P(X =x)
	-4	0.3	-1.2	4.8
	-3	0.1	-0.3	0.9
	-2	0.1	-0.2	0.4
	-1	0.2	-0.2	0.2
	0	0.3	0	0
Total	-10	1	-1.9	6.3

As sum of All probability is 1 so it is probability distribution

Mean Of X = µ	=	Σ x * P(X=x)            =	-1.9
Variance of X    = σx^2	=	Σ x*x * P(X=x)   - µ^2    =	6.3 - -1.9*-1.9     =	2.69
Standard deviation X    = σx^2	=	SQRT(Variance)   =	1.640121947

Variance for give data is 2.69