Box & Whisker Plot

Box & Whisker PlotChantal Alano, Trisha Jiang, Jordan ArmstrongPeriod 1

What is a Box & Whisker Plot? Used when there is a large amount of data Shows:

Median(Q2) Minimum Maximum Lower Quartile(Q1) Upper Quartile(Q3) Sometimes outliers Inter Quartile Range (IQR)

What is the Inter Quartile Range (IQR)?Q3-Q1=IQR

Example 7, 7, 9, 9, 10, 10, 11, 11, 12, 13 Used to find number of sled dogs left

competing in race

Data Necessary Single Sets Multiple Sets Numerical

Real Life Data Data was collected from Arcola’s 7th

grade Honors Algebra classHours of Electronics Used Per Day 2.5, 4.5, 4.5, 1, 1.5, 1, 3, 2, 1, 6, 3, 2, 3,

1, 3, 5

Real Life Data (cont.) What is the interquartile range (IQR) of

this data set?Q1 = 1.25

Q3 = 3.75

Median = 2.75 Max. = 6 Min. = 1

Hours of Electronics Used Per Day

Interquartile range: 3.75-1.25=2.5

How to Make a Box PlotHere is an example of a set of numbers collected.

2.5, 4.5, 4.5, 1, 1.5, 1, 3, 2, 1, 6, 3, 2, 3, 1, 3, 5Order the numbers

1, 1, 1, 1, 1.5, 2, 2, 2.5, 3, 3, 3, 3, 4.5, 4.5, 5, 6Find the median of the set

1, 1, 1, 1, 1.5, 2, 2, 2.5, 3, 3, 3, 3, 4.5, 4.5, 5, 6 Q2= (2.5 + 3)/2= 2.75

How to Make a Box Plot (cont.)Find the medians of the upper and

lower quartiles1, 1, 1, 1, 1.5, 2, 2, 2.5 and 3, 3, 3,

3, 4.5, 4.5, 5, 6The median of the lower quartile is:

Q1 = (1 + 1.5)/2 = 1.25The median of the upper quartile is:

Q3 =(3 + 4.5)/2 = 3.75

How to Make a Box Plot (cont.) Plot:

Median = 2.75 Q1 = 1.25 Q3 = 3.75 Maximum = 6 Minimum = 1

Draw tick marks indicating median, Q1, Q3, minimum, and maximum

Draw box around median, Q1, and Q3 Connect box to maximum and minimum

endpoints to create “whiskers”

Hours of Electronic Used Per Day

Advantages & DisadvantagesAdvantages

Able to tell median, range, lower quartile, upper quartile, minimum, and maximum

Not cluttered with too much information

Can show outliers

Disadvantages Doesn’t show

specific numbers Doesn’t show

subtle changes Can’t identify the

original numbers used in the data set

Research Page/ Work Cited http

://www.ck12.org/user:amhhdGVydEB5c3NjaG9vbHMub3Jn/section/Box-and-Whisker-Plots/

http://www.purplemath.com/modules/boxwhisk.htm

http://www.vertex42.com/ExcelTemplates/box-whisker-plot.html

http://www.edu.gov.mb.ca/k12/tech/lict/let_me_try/g6/mh132.html

Special Thanks To… Jordan Armstrong

Chantal Alano

Trisha Jiang

Mrs. Ellwood

Honors Algebra Class