+0

# Help needed plz thx

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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
+6196
+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
+1709
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How do you pay neg? Just curious.

tommarvoloriddle  Jul 25, 2019
#3
+26006
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I believ it just means you are PAYING MORE than the expected return....by 8 cents

ElectricPavlov  Jul 25, 2019
#4
+1709
0

I think that the company pays you.

tommarvoloriddle  Jul 25, 2019
#5
+6196
+1

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

Rom  Jul 26, 2019