1. STATISTICS Stem and Leaf Diagrams Objectives Understand and use a stem and leaf diagram 15 Aug 2011 © Brain-Cells: E.Resources Ltd. All Rights Reserved 24/11/09 www.brain-cells.co.ukwww.brain-cells.co.uk

2. 138 2145 32679 45 Stem and Leaf Diagrams Use a stem and leaf diagram to record the numbers: 13, 18, 21, 24, 25, 32, 36, 37, 39 and 45 The numbers in red are the stem. These are units of ten. The numbers in green are the leaves. These are the units What is the median number? The two middle numbers are 25 and 32 so add then divide by 2. (25 + 32) ÷ 2 57 ÷ 2 = 28.5 © Brain-Cells: E.Resources Ltd. All Rights Reserved 24/11/09 www.brain-cells.co.ukwww.brain-cells.co.uk

3. Back to Back Stem and Leaf Here are the ages of men and women at a gym Men 18, 22, 24,. 33, 33, 35, 37 41, 43 47 Women 17, 18, 21, 23, 23, 24, 25, 31, 32 Put this data onto a back to back stem and leaf diagram WomenMen 8 1 8 3345 2 24 12 3 3 4 1 Copy and complete and find the mode median, mean and range for men and women. Comment on the results © Brain-Cells: E.Resources Ltd. All Rights Reserved 24/11/09 www.brain-cells.co.ukwww.brain-cells.co.uk

4. Back to Back Stem and Leaf Here are the ages of men and women at a gym Men 18, 22, 24,. 33, 33, 35, 37 41, 43 47 Women 17, 18, 21, 23, 23, 24, 25, 31, 32 Put this data onto a back to back stem and leaf diagram WomenMen 78 1 8 13345 2 24 12 3 3357 4 137 ModeMedianMeanRange Men333433.329 Women23 23.815 Comment: The average woman is approximately ten years younger than the average man © Brain-Cells: E.Resources Ltd. All Rights Reserved 24/11/09 www.brain-cells.co.ukwww.brain-cells.co.uk