Chapter 9: Statistics

Statistics covers organising raw data into a grouped frequency distribution, presenting it as bar graphs and histograms, and calculating the mean, median and mode of ungrouped data by several different methods.

This chapter extends Class 8's Frequency Distribution Tables and Graphs to genuinely larger datasets, and leads directly into Class 10's Statistics, where the same three measures get extended to grouped data with dedicated formulas. Miscounting frequencies while tallying a large dataset, and mixing steps from two different mean-calculation methods partway through, are the two most frequent sources of error.