Activity 1: How did I do? How well did you do on the Chapter 1 Test? How well did you do relative to your classmates? Here are the results of a random sample of 20 of the Chapter 1 Tests, along with a dotplot and summary statistics. Test Scores 61 65 65 73 75 77 78 78 79 80 80 80 80 81 81 88 89 93 98 99 n mean SD min Q1 med Q3 max OO 20 80 10 61 76 80 84.5 99 60 65 70 75 80 85 90 95 100 Chapter 1 Test Scores 1. Biff scored a 65. What is Biff's percentile? (percentile: percent of values less than or equal to that value) 2. Was Biff above or below the mean? By how many points? By how many standard deviations? 3. Marty scored an 88. What is Marty's percentile? 4. Was Marty above or below the mean? By how many points? By how many standard deviations? A z-score is defined as the number of standard deviations above or below the mean. 5. Write a formula for calculating a z-score. Z = 6. Goldie scored a 98 on the Chapter 1 Test. Find and interpret the z-score