Question

Dave counted the number of peanuts in each bag of trail mix. Number of peanuts Number of bags 51 1 74 6 107 3 X is the number of peanuts that a randomly chosen bag had. 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)`

We have to multiply each value by its probability and sum them all

`\begin{gathered} E=51\cdot(1)/(10)+74\cdot(6)/(10)+107\cdot(3)/(10) \\ E=5.1+44.4+32.1 \\ E=81.6 \end{gathered}`

Hence, the expected value is 81.6.