Your child is learning about scatter plots and ...©Curriculum Associates, LLC Copying is not...
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Dear Family, ©Curriculum Associates, LLC Copying is not permitted. 293 Lesson 28 Scatter Plots When you have a data set involving two variables, the data is called bivariate data. A scatter plot is a visual way to determine the association between two variables. The relationship between two variables is called their association. • A positive association exists when as one value increases the other value increases as well (for example, the relationship between calories burned and time spent exercising). • A negative association exists when as one value increases the other value decreases (for example, the relationship between the temperature outside and heating costs). • There is no association when there is no clear pattern of increase or decrease between the two variables (for example, the relationship between a person’s shoe size and salary). Consider the following example: The table shows the shoe size and height in inches for 10 boys. Shoe Size 9 12 6 8 10 12 75 9 11 105 Height (inches) 66 69 61 64 68 71 62 65 68 70 What is the association between a person’s shoe size and height based on the data? The next page shows how your child may use a scatter plot to decide whether there is an association between shoe size and height. Your child is learning about scatter plots and associations between two variables. Use with Ready Instruction Lesson 28
Transcript of Your child is learning about scatter plots and ...©Curriculum Associates, LLC Copying is not...
Dear Family,
©Curriculum Associates, LLC Copying is not permitted. 293Lesson 28 Scatter Plots
When you have a data set involving two variables, the data is called bivariate data. A scatter plot is a visual way to determine the association between two variables.
The relationship between two variables is called their association.
• A positive association exists when as one value increases the other value increases as well (for example, the relationship between calories burned and time spent exercising).
• A negative association exists when as one value increases the other value decreases (for example, the relationship between the temperature outside and heating costs).
• There is no association when there is no clear pattern of increase or decrease between the two variables (for example, the relationship between a person’s shoe size and salary).
Consider the following example:
The table shows the shoe size and height in inches for 10 boys.
Shoe Size 9 12 6 8 10 12 7 .5 9 11 10 .5
Height (inches) 66 69 61 64 68 71 62 65 68 70
What is the association between a person’s shoe size and height based on the data?
The next page shows how your child may use a scatter plot to decide whether there is an association between shoe size and height.
Your child is learning about scatter plots and associations between two variables.
Use with Ready Instruction Lesson 28
©Curriculum Associates, LLC Copying is not permitted.294 Lesson 28 Scatter Plots
Scatter Plots: Sample Solution
The table shows the shoe size and height in inches for 10 boys.
Shoe Size 9 12 6 8 10 12 7 .5 9 11 10 .5
Height (inches) 66 69 61 64 68 71 62 65 68 70
What is the association between a person’s shoe size and height based on the data?
Make a scatter plot of the data. Then look to see whether the data shows any trends.
Shoe Size
Hei
gh
t (in
ches
)
x
y
62
64
66
68
70
72
6O 7 8 9 10 11 12
The points appear to have an upward trend. It appears that as the first value increases, so does the second.
Answer: As shoe size increases, height also tends to increase. This shows a positive association between shoe size and height.
Vocabularyscatter plot a graph of ordered pairs in the coordinate plane that
represents the values of two variables .
bivariate involving two variables .
