Graphing

Read these sections and complete the questions at the end of each section. First, we'll look at the available methods to portray distributions of quantitative variables. Then, we'll introduce the stem and leaf plot and how to capture the frequency of your data. We'll also discuss box plots for the purpose of identifying outliers and for comparing distributions and bar charts for quantitative variables. Finally, we'll talk about line graphs, which are based on bar graphs.

Stem and Leaf Displays

Answers


  1. False: Stem and leaf displays can be unwieldy with large amounts of data because every single data value is shown in the figure.

  2. 132: The highest value is 132. You multiply the stem by 10 and add the leaf. For the highest value, this is (10)(13)+2.

  3. 4: There are four scores with a stem of four: 44, 47, 48, and 49.

  4. 6: The stems are multiplied by one, so the highest is (1)(6)+0.0.

  5. The stems are multiplied by one, so the lowest is (1)(-2) - 0.8. Note that with negative stems, the leaves are subtracted.

  6. True: Back-to-back stem and leaf displays are good for comparing two groups.

  7. False: Stem and leaf displays are not well suited for comparing three or more groups.