Use the following information to answer questions 7 8: The Old Folks Tour Bus drives people to the casino every day and monitors how much they won/lost every day. They have come up with the following table to describe the winning/losing tendencies of gamblers at the casino. Win/Loss -$1,000 -$500 $200 $100 $400 $800 Amount Probabili 0.10 0.15 7. What is the expected value of this distribution? (In other words, what is the expected win or loss amount? If your answer is negative, don't forget to include a minus sign). 8. What is the standard deviation of this distribution? (Round to the nearest penny) Use the following information to answer questions 9 12: The following joint probability distribution describes the number of bridesmaids and groomsmen at weddings. To avoid lengthy arithmetic, it assumes there are always 1, 2, or 3 bridesmaids and either 1, 2, or 3 groomsmen. # of Bridesmaids 9. What is the marginal probability that a wedding will have 2 bridesmaids? (Your answer will be between 0 and 100, so if you think there is a 26% probability, enter 26 as your answer. Do NOT enter 0.26 or 26%) 10. Suppose you know that a wedding is going to have 2 groomsmen; what is the expected number of bridesmaids that will be at that wedding? 11. Is the number of bridesmaids independent of the number of groomsmen? (So, are these two random variables independent?) (Yes or No) 12. What is the correlation between the number of bridesmaids and the number of groomsmen? (Hint: this will take a while to do. You need to rst calculate the expected value of each random variable, then the covariance between the variables, then each variables standard deviation, and then you can nd the correlation) (Your answer will be between -1 and 1)