Expected Values

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

The following table shows the probability distribution for the number of children in each family in the town of Crossville. What is the average number of children in this town?

• 1.9

• 0.3

• 2.1

• 3

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

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

In a state lottery, a single digit is drawn from each of four containers. Each container has 10 balls numbered 0 through 9. To play, you choose a 4-digit number and pay $1. If your number is drawn, you win $5000. If your number is not drawn, you lose your dollar. What is the expected value for this game?

• You are expected to lose 1 dollar each time you play.

• You are expected to lose 50 cents each time you play.

• You are expected to win 1 dollar each time you play.

• You are expected to lose 75 cents each time you play.

• $5

• $2.50

• -$2.50

• $0

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

• 85

• 83.2

• 87.1

• 84.4

Using a deck of Uno cards (108 cards: 25 of each color plus eight wild cards): A player pays $1.00 to play. A wild cards pay $11.00. Calculate the expected value for the player.

• The player loses about 9 cents per play.

• The player wins about 9 cents per play.

• The player loses about 90 cents per play.

• The player wins about 90 cents per play.

Tags

PS.SPMD.4

• -$0.50

• $0

• $0.50

• $1

Data was compiled and the number of goals for a hockey team per game and the corresponding probabilities are given below. If this hockey team plays an 82-game season, what is the expected cumulative goal total for the next season?

• 220

• 239

• 261

• 309

• 320