©G Dear 2009 – Not to be sold/Free to use Summary Statistics General Mathematics Preliminary Calculating the Mean Stage 6 - Year 11 Press Ctrl-A ©G Dear 2009 – Not to be sold/Free to use

Mode (1/1) The Mode is a measure of central tendency The Mode is the most common score, The score with the highest frequency. Example 1: 2, 3, 4, 5, 7, 7, 8. Mode = 7 Example 2: 2, 3, 4, 5, 7, 7, 8, 8. Mode = 7, 8 Polymodal

When to use Mean, Median & Mode (1/2) The Mean is NOT a good measure of central tendency if we have outliers. E.g. 2, 3, 4, 4, 6, 7, 9 Mean = 5 2, 3, 4, 4, 6, 7,44 Mean = 10 One extreme value has doubled the mean. Use the Median = 4

When to use Mean, Median & Mode (2/2) The Mean and Median may NOT be a good measure of central tendency if we are using Discrete data. E.g. Shoe Sales Shoe Sizes: 6, 6, 8, 9, 9, 9. Mean = 7.8 Median = 8.5 In terms of sales the Mode is meaningful. Mode = 9