Question

sally, a journalism student, counted the number of pages in several major magazines. Number of pages Number of magazines 118 4 152 4 169 2 is the number of pages that a randomly chosen magazine had. What is the expected value of X? write your answer as a decimal.

Answer 1

Let's begin by identifying key information given to us:

4 magazines have 118 pages

4 magazines have 152 pages

2 magazines have 169 pages

The expected value for X (in pages) is given by:

`\begin{gathered} P(118pages)=(4)/(10)=(2)/(5) \\ P(152pages)=(4)/(10)=(2)/(5) \\ P(169pages)=(2)/(10)=(1)/(5) \\ EV(x)=118*(2)/(5)+152*(2)/(5)+169*(1)/(5) \\ EV(x)=141(4)/(5)=141.80 \\ EV(x)=141.8 \end{gathered}`

The expected value of X is 141.8 pages