Chapter 16 Review Questions
1. You roll 2 dice. If the sum of the dice is: 2, 3, 4 you win $20. If the sum is 5, 6, 7, 8 you win $10. If the sum is 9, 10, 11 you lose $20. If the sum is 12 you lose $25. It costs $5 to play.
a) Create the probability distribution of the random variable, “winnings” , including the cost to play, for this game.
b) What is the expected value of the “winnings” for this game?
c) What is the mean of the “winnings” for this game?
d) What is the variance for the “winnings” for this game?
e) Is this game a “fair game”? Why or why not.
2. The weight of a suitcase checked onto a plane by a male, is a random variable with mean 42 pounds and standard deviation 16 pounds. The mean and standard deviation of the weight of a suitcase checked onto a plane by a female, is a random variable with mean 40 pounds and a standard deviation of 10 pounds. A married couple consists of one male and one female. All suitcases are independent or each other even if from the same person.
a) What is the mean and standard deviation for the weight of the suitcases for a married couple, with one suitcase per person?
b) What is the mean and standard deviation for the 6 suitcases checked onto the plane by 2 married couples, if each couple checked on 2 female suitcases and 1 male suitcase?
c) In a cost cutting move the airlines is now charging $1.50 per pound for checked luggage. What is the mean and standard deviation for the cost of:
i) a suitcase checked by a female
ii) 2 suitcases checked by a males
d) In an unexplained move, a worker at the airport adds a 5 pound graphing calculator to each male’s suitcase. What is the new mean and standard deviation for the weight of a male’s suitcases?
f) What are the mean and standard deviation for the weight of the suitcases of a married couple, if the man’s suitcase is given the 5 pound calculator added to it?