A grab bag contains 12 packages worth $.70 each, 15 packages $.40 cents each, and 25 packages worth $.30 each. What is the expected value if you have to pay $.50 to pick one package at random?

A.-$0.08

B.$0.01

C.$0.47

D.$0.00

i got 47 but i don't know it that is true can someone help me plz.

Guest Jul 25, 2019

#1**+2 **

\(N=12+15+25 = 52\\ P[70c]=\dfrac{12}{52}=\dfrac{3}{13}\\ P[40c]=\dfrac{15}{52}=\dfrac{5}{13}\\ P[30c]=\dfrac{25}{52}\\~\\ E=70 \dfrac{3}{13}+40 \dfrac{5}{13}+30\dfrac{25}{52}-50 = -\dfrac{205}{26}\approx -\$0.08\)

.Rom Jul 25, 2019

#3**+1 **

I believ it just means you are PAYING MORE than the expected return....by 8 cents

ElectricPavlov
Jul 25, 2019