Probability

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

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
• $5
• $7.50
• $10

Tags

CCSS.7.NS.A.3

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 $1.50
• win an average of $2.00
• lose an average of $10.00

A horse's odds of winning a race are quoted at 7:2. What is the probability that the horse wins the race? Round to the nearest percent.
[Odds in horse racing are always odds against.]

• 22%
• 28%
• 78%
• 72%

The odds in favor of rain tomorrow are 6:11. What is the probability of rain tomorrow? Round to the nearest percent.

• 35%
• 55%
• 65%
• 85%

What is the probability that a female is chosen given they like a Toyota? 

• .525
• .4627
• .6774
• .3143

What is the probability that they speak French given that they are a girl? 

• 2.14
• .24
• .4
• .8571

What is the probability that the person picked will be a boy given they speak german? 

• .7273
• .4
• .16
• .22

What is the probability of rolling a dice and landing on a 4, and then rolling the dice again and landing on any even number?

• 1 ⁄ 6
• 1 ⁄ 8
• 1 ⁄ 2
• 1 ⁄ 12

A jar contains 4 white chips, 5 purple chips, and 1 black chip. Chips are selected randomly one at a time, and are not replaced. P(purple then black)

• 1/18
• 2/5
• 3/7
• 4/9