Section 13.7 Stem and Leaf and Histograms Objective: Students will make stem and leaf plots and histograms and use these to answer data questions. Standard: S.ID.1, S.ID.2

Vocabulary Stem and leaf Plot: A data display that organizes data based on their digits. Shows how the data are distributed. Histogram: Bar graph that groups data into equal intervals. There are not spaces between the bars. Helps if you write the numbers IN ORDER!

Example 1 Make a stem and leaf plot for the following: 60, 63, 64, 68, 60, 62, 59, 70, 64, 66, 58, 72, 64 Step 1: Write numbers in order first: 59, 60, 62, 63, 64, 66,68, 70, 64, 58, 72 Step 2: Put into stem and leaf plot: For 2 digit Number: First digit of each number is a STEM Second digit of each number is a LEAF. StemLeaves

Example 1 cont, Find median and range: 59, 60, 62, 63, 64, 66,68, 70, 64, 58, 72 Median: 64 Range: 72 – 58 = 14

Example 2 Make a histogram for the following: 7, 12, 29, 15, 8, 2, 0, 17, 22, 25, 28, 8, 11, 10 Step 1: Choose intervals of EQUAL SIZE: Range: 29 – 0 = 29 Can divide RANGE by the number of intervals you want to have, or just look at data and decide for yourself. This is about 30 so: 30 ÷ 3 = 10 we can go by 10’s Step 2: Organize data using FREQUENCY table – this tells how many values fall in the intervals. IntervalsFrequency (tallies) | | | | || | | | | | |||

Example 2 cont. Step 3: Draw the bars of the histogram using the intervals from the frequency table. IntervalsFrequency (tallies) | | | | | | | | | | | ||| Range

Example 2 cont, Find median and range: 2, 7, 8, 10, 11, 12, 17,22, 25, 15, 0, 28, Median: 11.5 Range: 29 7, 12, 29, 15, 8, 2, 0, 17, 22, 25, 28, 8, 11, 10 29

Homework Section 13.6 Pg. 883 Make stem and leaf AND histograms for Then find median and range : 3 – 5, 11, 12 Follow directions: 8, 9, 10