Expected Value

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

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CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

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

• yes
• no

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CCSS.HSS.MD.B.5

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

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CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

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

• 85

• 83.2

• 87.1

• 84.4

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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

Tags

TEKS.MATH.7.3B

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

• 1.75
• 1.84
• 2.00
• 2.50

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CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

x               100      200     300    400
P(X=x)       0.1      0.7      0.1     0.1
Find the expected value.

• 220
• 230
• 150
• 250

Expected value is the ________ one can expect over many repeated trials.

• best outcome

• total combination of outcomes

• average outcome

• worst outcome

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CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

Which of the following best describes how to calculate expected value?

• Add each possible outcome together, and multiply the sum by the probability of the least likely outcome.

• Multiply each possible outcome by its probability, and add each product together.

• Multiply each possible outcome by itself, and add each product together.

• Add each probability together, and multiply it by the sum of each possible outcome.

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Possible outcomes should always account for ________ when calculating expected value.

• exchange rate

• time

• inflation

• cost to play

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CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5