Geometric Probability & Expected Value

If the expected value is negative, are you expected to win?

• yes
• no

A coin is flipped 3 times. If you get tails once you get $5, tails twice you get $15, and tails on all three flips you get $40. What is the expected amount of money you will get?

• $12.50

• $11.25

• $7.50

• $10

Eva flips a coin. If she gets heads, she wins $4. If she gets tails, she loses $3. What is her expected value of a coin flip?

• $1

• $0.50

• -$0.50

• $0

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. How much money do you take home (after paying for it)?

• $800

• -$6.50

• -$6

• -$5.20

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. Do you expect to win or lose (on average)? How much?

• lose an average of $5.50

• lose an average of $1.50

• win an average of $2.00

• lose an average of $10.00

A stockbroker estimates that at the end of the year, there is a 40% chance a stock will be worth $50, a 35% chance it will be worth $60 and a 25% chance it will be worth $70.
What expected value does this broker assign to this stock's end-of-the-year price?

• $58.50
• $60.00
• $62.50
• $65.00

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

Find the geometric probability of a marble falling on the shaded region of the figure. 

• 75%
• 45%
• 50%
• 80%

If a stone is dropped at random on the arrangement of tiles shown, what is the probability the stone lands on a black tile?

• 5/9
• 4/9
• 1/2
• 1/9

This game board is made up of concentric circles. The center circle has a diameter of 4 inches. Each successive ring has a radius 2 inches greater than the ring before. Find the probability of scoring 80 points.

• 2/3
• 1/3
• 3/4
• 1/4