Education Technology

Describing One-Variable Data

Published on 06/09/2008

Activity Overview

Students sort data and display it graphically using various plots. They also get familiarized with statistical concepts like measures of spread and central tendency.

Before the Activity

  • See the attached PDF file for detailed instructions for this activity
  • Print pages 11 - 22 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to the class.

    Follow the Activity procedures:

  • Enter the data of building heights as lists
  • Plot the frequency data as a histogram
  • Create a frequency table
  • Observe the effects of changing the class width on the histogram


  • Using the lower and upper class limits in the frequency table and calculate the class marks
  • Use the frequency table to calculate the relative frequencies and find the percent of buildings in a class
  • Plot the relative frequency data as a histogram


  • Make a copy of the list containing the data for the heights of buildings
  • Sort the data in ascending order
  • Create a Stem-and-Leaf Plot
  • Generate a Dot Plot


  • Use the listed data or the frequency table to calculate the common measures of central tendency (mean and median) and the measures of spread or variability (standard deviation, variance, interquartile range, and five-number summary)


  • Use the mean and the standard deviation to determine the standard scores of the smallest and tallest buildings
  • Observe how many standard deviations away these values are from the mean
  • Decide whether the data distribution is symmetric or skewed
  • Find percentiles and quartiles
  • Create a frequency table and calculate the cumulative relative frequencies
  • Set up an xy line plot to find the percentile value for a building of given height


  • Use the data to set up a modified box plot
  • Calculate a five-number summary
  • Draw a box plot and view it along with a histogram
  • Generate multiple box plots, side by side
  • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary