The following data were obtained from a survey of college st

The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.

x

0

1

2

3

4

5

6

P (X=x)

0.55

0.15

0.10

0.10

0.04

0.03

0.03

What is the expected value of X?

Solution

E(x)= 0*0.55+1*0.15+2*0.10+3*0.10+4*0.04+5*0.03+6*0.03 =1.14