Displaying Quantitative Data: Histograms
Day 7 - Lesson 1.5
Make histograms of quantitative data.
Compare distributions of quantitative data with histograms.
Have students get out their phones and estimate how many text messages they sent yesterday. “But what about group chats…do those count?” Absolutely. The number of students with over 100 amazed and surprised us. Students used the SPA applet to quickly create a histogram. Be sure that when they are describing the distribution that they address shape, center, variability, and outliers. The shape of the distribution changed a bit when students changed the widths of the intervals.
How Old Are U.S. Presidents?
This is a great data set. Turns out to be fairly symmetric. We try to get students in the habit of using –ly words when describing shape. Fairly symmetric, slightly skewed left, approximately normal. A distribution is rarely going to be exactly symmetric or exactly normal. The –ly word softens the response a bit.
This might be a good time to connect Lessons 1.3, 1.4, and 1.5. All three lessons are dedicated to displaying quantitative data (with dotplots, stemplots, and histograms). Discuss the pros and cons of each. Dotplots and stemplots show us all of the individual values, where a histogram does not….but a histogram might do a better job of displaying the shape of the distribution.