1. Lesson 11.2
Objective: To draw a box and whisker plot from a data list.
EQ: How many sections are there in a box and whisker plot?
Vocabulary:
Box-and Whisker Plot: is a data display that divides a set of data into four parts. Each part represents 25% of the data.
Least number
1st quartile
Highest number
2nd Quartile
3rd Quartile

2. EX: make a box and whisker plot for the data set
5, 7, 9, 11, 11, 12, 16, 17, 19, 25, 28, 34
Third Quartile 22
First Quartile 10
Second Quartile 14
Least 5
Highest 34
14 is the median, 50% of the data is below while 50% is above
Each section is 25 % of the data

3. EX: Test scores are given below, make a box and whisker plot and answer the following questions.
54, 62, 71, 74, 76, 78, 82, 82, 84, 88, 89, 90, 91, 92 , 92, 93, 95, 96
3rd quartile
1st quartile
2nd quartile
1) What percent scored above 76 % ?
75%
2) What percent scored above 86 % ?
50%
3) How many students scored less than 86 % ?
9 students
4) What is the range of scores ?
96 – 54 = 42
5) What is the interquartile range (3rd quartile – 1st quartile) ?
92 – 76 = 16
6) 54 is almost an outlier. Multiply 1.5 by interquartile range to determine the distance a number must be from edge of box to not be an outlier.
16 x 1.5 = – 24 = 52 so anything less than 52 would have been an outlier.

4. Outliers: are numbers that are too far from the rest of the data
Officially outliers are the distance more than 1.5 times interquartile range beyond the 1st or 3rd quartiles.
EX: Find the median, range, quartiles, inter quartile range and outliers. Then create a box and whisker plot.
16, 18, 23, 24, 32, 39, 41, 46, 196
Outlier
1st Q
20.5
3rd Q
43.5
2nd Q
Range 180
interquartile range 23

5. Draw a line down middle of the plot to determine how its skewed.

6. After watching the video
After watching the video. Be able to tell what measure of central tendency outliers have the greatest impact on.