Expected Value and Games of Chance

A student group sells 500 raffle tickets for $2 each. At the drawing the top prize will be a gift certificate for $100. Second prize will be a $50 gift card and there will be five 3rd prizes, each a $20 gift card. What is the expected value of a ticket?

• lose an average of $5.50
• lose an average of $1.66
• win an average of $2.00
• lose an average of $10.00

Suppose you buy a ticket for $6 out of a lottery of 1000 tickets where the prize for the one winning is to be $800. What are your expected winnings (on average)?

• $800 
• -$6.50
• -$6
• -$5.20

Given the probability model in the table below, what is the expected value of the random variable?
  X        50          20        5
P(X)     0.1         0.3      0.6

• 14
• 4.67
• 5
• 7.5

For several days you record about how long it takes to get to school and recorded your results in a table.
    Time                           Number of days
5 - 7 minutes                           1/23
7 - 8 minutes                           4/23
8 - 9 minutes                           7/23
9 - 10 minutes                         9/23
10 - 12 minutes                       2/23

How long does it take you to get to school on average?

• 9.8 minutes
• 9.2 minutes
• 5.5 minutes
• 8.8 minutes

Tags

CCSS.5.MD.B.2

Juan is playing a game in which he can win $100.00 with probability .1, $200.00 with probability .2 or $300.00 with probability .7. What is the expected value of Juan's Winnings? If he plays 5 times how much should he win?

• 260 , 1300
• 520 ,  2600
• 100 , 500
• 25 , 125

What is the expected value of rolling a die? 

• 3.5
• 3.45
• 3.6
• 3