So we take a sample , a subset of the population, from which data are obtained. Conclusions derived from the sample is thought to apply to the population. The task of summarizing a data set is to describe its distributional characteristics. We consider graphical, tabular and numerical methods to describe data distribution. Example 1a .
List stems from smallest to largest in a column.
Write each leaf to the right of its stem. Sort leaves from smallest to largest. Shrinkage Data Example 1b . 335699 Group A Group B Frequency Distribution Divide the data range into intervals of equal length. Count the number of observations for each interval.