Question

Mariana, who rents properties for a living, measures all the offices in a building she is renting. Size (square meters) Number of offices 60 3 70 2 98 5 X is the size of a randomly chosen office. What is the expected value of X? Write your answer as a decimal.

Answer 1

The expected value formula is

`E=\Sigma x\cdot P(x)`
`\begin{gathered} E=60\cdot(3)/(10)+70\cdot(2)/(10)+98\cdot(5)/(10) \\ E=18+14+49 \\ E=81 \end{gathered}`

Hence, the expected value is 81.