Chapter 16 Random Variables Review

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

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

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

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

• yes
• no

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

• yes
• no

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

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

Tags

CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

A small store keeps track of the number X of customers that make a purchase during the first hour that the store is open each day. Based on the records, X has the following probability distribution. What is the average number of customers that the owner can expect to make a purchase in the first hour of opening?

• 0.2

• 1.4

• 2.0

• 3.0

Tags

CCSS.HSF-LE.A.1B

Given the probability model in the table below, what is the expected value of the random variable?

• 12

• 4.67

• 14

• 7.5

Tags

CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

A child asks his parents for some money. The parents make the following offers.
 Father’s offer: The child fl ips a coin. If the coin lands heads up, the father will give the child $20. If the coin lands tails up, the father will give the child nothing.
Mother’s offer: The child rolls a 6-sided die. The mother will give the child $3 for each dot on the upside of the die.
Which offer has the greater expected value?

• Mother's Offer
• Father's Offer