Question

Consider the following data:

x	2	3	4	5	6
P(X=x)	0.3	0.2	0.2	0.1	0.2

Step 1 of 5 : Find the expected value E(X). Round your answer to one decimal place.

Answer 1

X	P(X)	X*P(X)	X² * P(X)
2	0.3	0.6	1.200
3	0.2	0.6	1.800
4	0.2	0.8	3.2000
5	0.1	0.5	2.5000
6	0.2	1.2000	7.2000

expected value = mean = E[X] = Σx*P(X) =            3.70

========================

          
E [ X² ] = ΣX² * P(X) =            15.9000
          
variance = E[ X² ] - (E[ X ])² =            2.2100
          
std dev = √(variance) =            1.4866