Expected Value and Random Variables

Choose an American household at random. What is the expected number of cars for that household?

• 1.75
• 1.84
• 2.00
• 2.50

Tags

CCSS.HSS.MD.A.2

In a certain community, 30% of households have 1 child, 43% have 2 children, and 27% have 3 children. If a household is selected at random, what is the expected number of children in that household? HINT: A Probability table may be helpful.

• 2.00
• 2.13
• 1.97
• 1.27

Tags

CCSS.HSS.MD.A.2

Find the expected value. READ CAREFULLY!

• 4.5
• 25.5
• 3.825
• 6.52

Tags

CCSS.HSS.MD.A.2

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

Tags

CCSS.HSS.MD.B.5A

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

Tags

CCSS.HSS.MD.B.5A

Find the mean (expected value) of the probability distribution.

• 85

• 83.2

• 87.1

• 84.4

Tags

CCSS.HSS.MD.A.2

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

• yes
• no

Tags

CCSS.HSS.MD.A.2

A game consists of rolling a colored die with three red sides, two green sides, and one blue side. A roll of a red loses. A roll of green pays $2.00. A roll of blue pays $5.00.   The charge to play the game is $2.00. What is the expected value

• $0
• -$0.50
• $.67
• $-1.50

Tags

CCSS.HSS.MD.B.5A

The table represents the probability of guessing correct on a 5 question true-false quiz.  Find the probability for at least 4 questions correct.

• .03125
• .15625
• .3125
• .1875

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.4

A marketing survey compiled data on the number of cars in households.  If X = the number of cars in a randomly selected household, and we omit the rare cases of more than 5 cars, then X has the following probability distribution: 
X           0          1          2          3           4           5    
P(X)   0.24    0.37    0.20    0.11    0.05     0.03
What is the probability that a randomly chosen household has at least two cars?

• 0.20
• 0.29
• 0.39
• 0.61

Tags

CCSS.HSS.MD.A.3

CCSS.HSS.MD.A.4