2 3 StemandLeaf Displays StemandLeaf Displays Used to

2. 3 Stem-and-Leaf Displays

Stem-and-Leaf Displays • Used to rank-order and arrange data into groups • Used to detect patterns and extreme data values • Useful when data are gathered for general interest and observation of subjects (no specific questions in mind) • Sometimes used to make frequency tables easier • In histograms, we lose specific data. Stem-and-leaf displays allow us the ability to retrieve original data.

How to Create a Stem-and-Leaf Display: 1. Divide the digits into two parts (stem → left, leaf → right) 2. Align the stems in a vertical column from smallest to largest. Draw a vertical line to the right of the stems. 3. Place leaves in the appropriate stem row and order from least to greatest. 4. Use a label to show the meaning and units of the stem and leaf. i. e. Stem Leaves 0 1 2 Example #5 p. 57 268 245 016 1 2 represents 12 packages

How do we divide the stem and leaves? *Guided exercise #4 How to Split a stem: When a stem has many leaves, split the stem into multiple lines. For two lines per stem, use 0 to 4 for one line and 5 to 9 for the next. i. e. Stem Leaves 1 00122223344 1 555678899 2 1269

Back-to-Back Stem Plot • Useful when comparing similar data from two populations Leaf 1 Stem Leaf 2 10 2 0023 311 3 2 2 4 03 5 2 0 represents 25 for Leaf 1 and 20 for Leaf 2

Homework: • p. 61 - 64 #1, 2, 5, 10