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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.

 Jul 25, 2019
 #1
avatar+6250 
+2

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

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 Jul 25, 2019
edited by Rom  Jul 25, 2019
 #2
avatar+1713 
+1

How do you pay neg? Just curious.

tommarvoloriddle  Jul 25, 2019
 #3
avatar+37153 
0

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

ElectricPavlov  Jul 25, 2019
 #4
avatar+1713 
0

I think that the company pays you.

tommarvoloriddle  Jul 25, 2019
 #5
avatar+6250 
+1

it means on average you win less than the 50c you paid to play.

Rom  Jul 26, 2019

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