Homework Probability 3 (5 Questions) 1. Which of the expressions below could be used to answer the following question? Mrs. Rogers is separating her students into groups of 4. She has 18 students in class. How many different arrangements of students are there for the first group? Everyone is an equal member of the group, there are no specific roles, and she is choosing students randomly. A. 18!/4!14! B. nCr(18,4) C. 18! /14! D. nPr (18,4) 2. The following table shows the number of students in Mr. Morales' class that are ages 15, 16, and 17. What is the expected age of a student randomly chosen from the class? Round your answer to the nearest tenth (1 decimal place). # of Age Students 15 9 16 11 17 3 3. Sam owns a store that sells items for $1, $5, and $10. The following table shows what percentage of his sales are from each price group. What is the expected price of an item sold in Sam's store? A. $5.33 B. $1.00 C. $4.03 D. $7.50 4. Ms. Danvers is playing a game with her friend Ms. Rameau. On her next turn, Ms. Danvers can earn -2, 0, 5, or 8 points. The probability of each score is listed below. What is the expected point value of Ms. Danvers' next turn? Points Probability -2 22% 33% 40% Go 5% . 3.67 B. 5.00 C. 1.96 D. 2.75 5. Which expression would you use to find the answer to the following question? A DJ has a list of 1000 songs she can play. In a two-hour party, she can play 40 songs and she does not want to repeat any songs. How many unique playlists (if you change the order of the songs, it would be considered a different list) can she create from the list of 1000? A. 1000*40 B. 1000! /960! C. 1000! /40!960! D. 100040