AP Statistics Chapter 1-6 Review

How would you interpret the expected value in number 3?

• The maximum number of cars for the household is Exp(C).

• The average number of cars for the household is Exp(C).

• If we randomly select many households, the average number of cars per household will be approximately by Exp(C).

• If we randomly select many households, the average number of cars per household will vary approximately by Exp(C).

A deck of cards contains 52 cards , of which 4 are aces. You are offered the following wager: Draw one card at random from the deck. You win $10 if the card drawn is an ace. Otherwise, you lose $1. If you make this wager very many times, what will be the mean amount you win?

• About -$1, because you will lose most of the time.

• About $9, because you win $10 but lose only $1.

• About -$0.15; that is, on average you lose about 15 cents.

• About $0.77; that is, on average you win about 77 cents.

• About $0, because the random draw gives you a fair bet.

The number of calories in a 1-ounce serving of a certain breakfast cereal is a random variable with mean 110 and standard deviation 10. The number of calories in a cup of whole milk is a random variable with mean 140 and standard deviation 12. For breakfast, you eat 1 ounce of the cereal and 1/2 cup of whole milk. Let T be the random variable that represents the total number of calories in this breakfast. The mean of T is...

• 110

• 140

• 180

• 195

The number of calories in a 1-ounce serving of a certain breakfast cereal is a random variable with mean 110 and standard deviation 10. The number of calories in a cup of whole milk is a random variable with mean 140 and standard deviation 12. For breakfast, you eat 1 ounce of the cereal and 1/2 cup of whole milk. Let T be the random variable that represents the total number of calories in this breakfast. The standard deviation of T is...

• 22

• 16

• 15.62

• 11.66

It turns out that 25 seniors at Fashionable High School took both the AP Statistics exam and the AP Spanish Language exam. The mean score on the Statistics exam for the 25 seniors was 2.4 with standard deviation of 0.6, and the mean score on the Spanish Language exam was 2.65 with a standard deviation of 0.55. We want to combine the scores into a single score. What are the correct mean and standard deviation of the combined scores?

• 5.05; 1.15

• 5.05; 1.07

• 5.05; 0.66

• 5.05; 0.81

• 5.05; You cannot determine the standard deviation from this information.

Which of the following is a discrete random variable?

• I only

• II only

• III only

• I and II

• II and III

The following table gives the probabilities of various outcomes for a gambling game. What is the player's expected return on a bet of $1?

• $0.05

• -$0.60

• -$0.05

• -$0.10

• You can't answer this question since this is not a complete probability distribution.

A certain vending machine offers 20-ounce bottles of soda for $1.50. The number of bottles X bought from the machine on any day is a random variable with mean 50 and standard deviation 15. Let the random variable Y equal the total revenue from this machine on a given day. Assume the machine works properly and that no sodas are stolen from the machine. What are the mean and standard deviation of Y?

• Mean Y = $1.50 and St. Dev Y = $22.50

• Mean Y = $1.50 and St. Dev Y = $33.75

• Mean Y = $75 and St. Dev Y = $18.37

• Mean Y = $75 and St. Dev Y = $22.50

• Mean Y = $75 and St. Dev Y = $33.75

Seventeen people have been exposed to a particular disease. Each one independently has 40% chance of contracting the disease. A hospital has the capacity to handle 10 cases of the disease. What is the probability that the hospital's capacity will be exceeded?

• 0.011

• 0.035

• 0.092

• 0.965