Expected Value Practice

Suppose you pay $1.00 to roll a fair die with the understanding you will get $3.00 back rolling a 4 or a 2, and nothing otherwise.  What is the expected amount you win?

• $0.00
• -$1.00
• $1.00
• $3.00

In a school, 10% of students have 7 ball pens, 30% of students have 3 ball pens, 40% of students have 2 ball pens and 20% of students have 1 ball pens. What is the expected number of ball pens of a student?

• 2.4

• 2.8

• 2.6

• 3.0

If the expected value of a game is negative then:

• The player will lose money
• The player will win money
• The player will break even

Name a situation in real life that you could use expected value on.

• carnival games
• sports
• placing bets
• all of the above

Tags

CCSS.8.EE.C.7B

What do you need to determine before you can calculate expected value?

• number of people playing
• probability of winning 
• name of game
• names of people playing

Once you have probability, what else do you need to know to calculate expected value?

• cost of prize
• type of prize

On a spinner, red is 40% of the wheel, yellow is 15% of the wheel, and green is the rest of the wheel. Landing on red wins $23, landing on yellow wins $175 and landing on green loses $50. What is the expected value of the wheel?

• $8.92
• $12.95
• $10.67
• $94.08

“Wheel of Fortune” just got a new wheel! On it there are 6 slots worth $200, 15 slots worth $400, 2 slots worth $600, 1 slot worth $1000, 6 slots with no money, and 1 slot with a car worth $20,000. What is the expected winnings on one turn(cash and prizes)?

• $815.96
• $895.34
• $785.62
• $948.39

When a game is considered to be a "fair game," what do we know about the expected value?

• It is positive

• It is negative

• It is zero

• It is fun to play

You calculate an expected value for a carnival game and it ends up being $-1.25. What does this expected value tell us?

• We are expected to win $1.25 if we play this game

• The game is a fair game

• We are expected to lose $1.25 if we play this game.

• The cost to play this game is $1.25.