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Box Plots
How to create Box Plots
Bell Ringer
(review: how to calculate median values)
• Ashley’s Dress shop posted sales for one week of $874, $1471, $1275,
$1078, $993, $471, and $1125. Find the median sales for the week.
Ashley’s Dress shop posted sales for one week of $874, $1471,
$1275, $1078, $993, $471, and $1125. Find the median sales for
the week.
Solution:
Step 1: Order the numbers in ascending order
$471 + $874 + $993 + $1078 + $1230 + $1657
Step 2: Since there are 6 numbers, we must add the 3rd and 4th number to
calculate the median value.
$471 + $874 + $993 + $1078 + $1230 + $1657
Step3: Add the 3rd and 4th numbers.
$993 + $1078 = $2071
Step 4: Divide the answer by 2
$2071/2 =
Step 5: Solution
Ashley’s Dress shop weekly median total is $1035.50 dollars.
Introduction
How to create Box Plots
Lesson Objectives
Learning Goals *Calculate and identify the values of the key components of a box plot
*Construct and compare multiple data sets using Box Plots
Introduction
How to create Box Plots
Key Terms
• Minimum value
• Maximum Value
• Range
• Median value
• Outlier
• Lower Quartile (Q1)
• Upper Quartile (Q3)
• Interquartile Range (IQR)
I DO
Given a set of data, Find the Lower, Median, and Upper Quartiles
7, 13, 11, 5, 9, 10, 4, 2
Step 1: Order the data
2, 4, 5, 7, 9, 19, 11, 13
Step 2: Separate the value in two equal groups and label them.
2, 4, 5, 7
11, 13, 11, 19
I DO
Given a set of data, Find the Lower, Median, Upper Quartiles and
Interquartile Range (IQR)
(Q1, M, Q3, and IQR, respectfully)
Step 3: Label each group of values
Q1: 2, 4, 5, 7
M: 7, 9
Q3: 9, 11, 13, 19
Step 4: Determine the median value for each of the three groups and
the Interquartile Range (IQR)
Q1 = 4.5 M = 8
Q3 = 10.5
IQR = Q3-Q1 = 10.5-4.5 = 6
We Do
Lets try it together using the steps that were outlined
Given a set of data
1, 14, 5, 10, 3, 7, 12, 17
Step 1: Order the data in ascending order
1, 3, 5, 7, 10, 12, 14, 17
Step 2: Separate the data into equal groups
1, 3, 5, 7
10, 12, 14, 17
We Do
Step 3: Label the groups
Q1: 1, 3, 5, 7
M: 7, 10
Q3: 10, 12, 14, 17
Step 4: Determine the median value for each of the three groups and the
Interquartile Range (IQR)
Q1 = 4
M = 8.5
Q3 = 13
IQR = 9
I Do
Using the given data, Create a Box Plot
7, 13, 11, 5, 9, 10, 4, 2
Step 1: Plot the points on a real number line
I DO
Using the given data, Find the Q1, M, and Q3
7, 13, 11, 5, 9, 10, 4, 2
Step 2:
Step 3:
Q1 = 4.5
M=8
Q3 = 10.5
IQR = 6
Identify the Q1, M, and Q3 values on the number
I DO
Step 4: Create the Box Plot
We Do
Using the given data, Create a Box Plot
1, 14, 5, 10, 3, 7, 12, 17
Step 1: Plot the points on a real number line
We Do
Lets try it together using the steps that were outlined
Using the given data, Find the Q1, M, Q3, and IQR
7, 13, 11, 5, 9, 10, 4, 2
Step 2: Q1 = 4
Step 3:
M = 8.5
Q3 = 13 IQR = 9
Identify the Q1, M, and Q3 values on the number
We Do
Step 4: Create the Box Plot
They Do
Try this in your group:
Using the given data, Find the Q1, M, Q3, IQR and create a Box Plot
21, 25, 15, 13, 17, 19, 19, 21
They Do
Q1 = 16
M = 19
Q3 = 21
IQR = 5
Closure
• How is a Line plot similiar to a Box plot?