1. Box-and-Whisker Plots Emily Billoch, Isabela Fernandez Sebastian Pinto, Robert Fridel P.5

2. What is a box-and-whisker plot graph?  A graph that summarizes a set of data by displaying it along a number line. Three Parts :  A box  2 whiskers

3. Vocabulary Quartiles You have three points: the first middle point (the median), and the middle points of the two halves (what I call the "sub-medians"). These three points divide the entire data set into quarters, called "quartiles". The top point of each quartile has a name, being a "Q" followed by the number of the quarter. So the top point of the first quarter of the data points is "Q 1 ", and so forth. Note that Q 1 is also the middle number for the first half of the list, Q 2 is also the middle number for the whole list, Q 3 is the middle number for the second half of the list, and Q 4 is the largest value in the list.

4. Interquartile Range In other words, the IQR is the 1st quartile subtracted from the 3rd quartile; these quartiles can be clearly seen on a box plot on the data. It is a trimmed estimator, defined as the 25% trimmed mid- range, and is the most significant basic robust measure of scale. 8-4=4

5. Percentile & Percentile Rank A percentile rank is the percentage of scores that fall at or below a given score. Definition 2: A percentile is a measure that tells us what percent of the total frequency scored below that measure. A percentile rank is the percentage of scores that fall below a given score.

6. STEP 1 Arrange the date in order from least to greatest. Example: 125, 80, 140, 135, 126, 140, 350, 75 75, 80, 125, 126, 135, 140, 140, 350

7. STEP 2 Find the minimum, maximum, and median. Example: Median(Q 2 ) = 126 +135 =130.5 The minimum is 75. The maximum is 350. The median is 130.5. 2

8. STEP 3 Find the first quartile and the third quartile. 75, 80, 125, 126, 135, 140, 140, 350 First quartile (Q 1 ) = 80+125= 102.5 Third Quartile (Q 3 ) = 140+140 = 140 The first quartile is 102.5. The third quartile is 140. 2 2

9. Try it yourself! 1) 12, 10, 11, 7, 9, 10, 5 Organize from least to greatest. 5, 7, 9, 10, 10, 11, 12 Find the minimum, maximum and median. 5, 7, 9, 10, 10, 11, 12 Minimum= 5 Median=10 Maximum=12

10. Find the first and third quartile. Q 1 = 7, 9 7+9 = 8 Q 3 = 10, 1110+11= 10.5 The first quartile is 8, the third quartile is 10.5. 2 2

11. Example 1 101, 100, 100, 105, 101, 102, 104

12. Example 2 21, 34, 20, 8, 15, 29, 52, 33

13. Example 3 100, 72, 89, 88, 175, 120, 110, 99