Lesson 2.2: Show and Describe Variability
Lesson
Introduction ![]400 Major hurricanes change lives in major ways depending on where they make landfall. Two large storms, Hurrican Katrina, which struck New Orleans in 2005, and Hurricane Sandy, which caused much damage in and around New York City in 2012, will be remembered for a long time because so many lives were disrupted. Questions students could ask of data about hurricanes might include the following: How typical are hurricanes like Katrina and Sandy? Did Katrina and Sandy last longer than most hurricanes? Did they have stronger winds than most hurricanes? How frequently do storms as strong as Katrina and Sandy occur? Looking at variability in a dataset can help to understand the phenomenon of major hurricanes. This lesson reviews how to visualize variability in data using dot plots, and how students can describe variability qualitatively and mathematically. Key Ideas for Students: Show distributions of data using a dot plot Describe variability in a distribution of data in lay terms (spread out, clumped, even, symmetrical, etc.) or in mathematical terms (range, mean, median, normal, bimodal, skewed, variance, standard deviation, etc.) Infer from a dot plot what is “typical” for a group Recognize variability as a useful collective property of data Key words: Bimodal, Dot Plot, Distribution, Distribution Shape, Frequency Plot, Mean, Median, Normal, Range, Skewed, Variability
Topics and standards: Variability