Lesson 2.3: Introduction to Box Plots
Lesson
Introduction In Variability - Lesson 2.2 you: Described typical values in a distribution by locating the “central clump” (the middle 50% of the data) using the dividers Decided which measure of center (mean or median) is best to use, based on the distribution shape In this lesson you’ll learn: How to show a distribution of data in a way that makes it easy to visually compare variability in two or more distributions. Use a box and whisker plot to show variability in a distribution. Read a box and whisker plot -- describe the range of the distribution, how spread out the middle 50% of the data is, and find the median Prerequisites Lesson 2.2 (What is 'typical'?) is strongly recommended. Lesson Keywords Box and whisker plot (‘box plot’): A way of visualizing a distribution of data that shows the range, the central spread (‘central clump’), and the median. Interquartile range(or IQR, or ‘the box’): The middle 50% of the data points (the ‘central clump’). The box shows r the spread of ‘typical values’. Median: The vertical line inside the box. Median is the measure of center that is the middle point in the distribution (or the lower of two middle points). Whiskers: The lowest 25% of the data values (the ‘first quartile’) and the highest 25% of the data values (‘fourth quartile’). Whiskers can be thought of as the ‘tails’ in a dot plot.