Data Representation, Permutations & Probability

Representing data

Data can be shown with histograms (where area represents frequency, using frequency density), stem-and-leaf diagrams, box-and-whisker plots and cumulative frequency curves. From a cumulative frequency curve you read off the median ($\tfrac{n}{2}$), quartiles ($\tfrac{n}{4}, \tfrac{3n}{4}$) and percentiles.