2. Modeling Distributions of Data Describing location in a distribution Chapter 2.1

3. Percentile The pth percentile of a distribution is the value with p percent of the observations less than it. Test scores example: 8994 76 85 82 68 75 76 85 98 97 82 83 84 82 85 86 77 91 90 69 70 72 85 84 What percentile is a score of 89? 85? 69?

4. Cumulative Relative Frequency Graphs “Ogives” The following table shows the ages of people on a commuter train one morning. Draw an ogive to show this information. Lets start by making a cumulative frequency table Age10-1920-2930-3940-4950-5960-6970-7980-89 # of People 3759156172143752210

5. Age# of People Cumulative Frequency% 10-1937 5 20-295937+59=9614 30-3915625237 40-4917242463 50-5914356784 60-697564295 70-792266499 80-8910674100 102030405060708090 100 200 300 400 500 600 700

6. Age# of People Cumulative Frequency% 10-1937 5 20-295937+59=9614 30-3915625237 40-4917242463 50-5914356784 60-697564295 70-792266499 80-8910674100 102030405060708090 10 30 50 70 90