1. 1 InterquartileRange Press Ctrl-A G Dear ©2010 – Not to be sold/Free to use Stage 4 Year 9

2. 2 InterQuartile Range (1/7) Interquartile Range (1/7) (The Range of the middle 50% of scores) IQR =Q3 – Q1 What are Q3 and Q1? Q1 is the lower quartile of 25 th percentile. Q3 is the upper quartile of 75 th percentile. Example 1 1, 3, 5, 6, 7, 8, 8 Median =6 Q3 = Middle of top half. 8 Q1 = Middle of lower half. 3 IQR = Q3 - Q1 = 8 - 3 = 5 End of Slide

3. 3 Interquartile Range (2/7) Example 2 2, 3, 6, 6, 7, 8. Median =6 Q3 = Middle of top half. 7 Q1 = Middle of lower half. 3 IQR = Q3 - Q1 = 7 - 3 = 4 Example 3 2, 3, 5, 6, 7, 9, 9, 10. Median =6.5 Q3 = Middle of top half. 9 Q1 = Middle of lower half. 4 IQR = Q3 - Q1 = 9 - 4 = 5 End of Slide

4. 4 Interquartile Range and Dot Plots (3/7) 012345678 Median Q1 Q3 IQR = Q3 – Q1 = 5 – 2 = 3 End of Slide

5. 5 Interquartile Range and Stem-and-Leaf (4/7) 012345012345 Stem Leaf 0126 13356 4457799 23468 5779 05 Median Q1 Q3 IQR = Q3 – Q1 = 38 – 13 = 25 End of Slide

6. 6 Interquartile Range - Box-and-Whisker (5/7) A A – Upper Extreme B – Lower Extreme C – Median D – Upper Quartile – Q3 E – Lower Quartile – Q1 B C D E End of Slide

7. 7 Interquartile Range - Box-and-Whisker (6/7) IQR = Q3 – Q1 = 13 – 3 = 10 Q3 Q1 0246810121416 End of Slide

8. 8 IQR – 5 Number Summary (7/7) 0246810121416 Q3 Q1 Upper Extreme Median Lower Extreme Lower Extreme, Lower Quartile, Median, Upper Quartile, Upper Extreme 1, 3, 8, 13, 16 End of Slide