Lesson 4.5 Scatter plots

Lesson 4.5 Scatter plots

Learning Goals:

• I can create and interpret scatter plots. 

• I can use trend lines to make predictions.

Vocab

• Scatter plot: a graph with points plotted to show a relationship between 2 sets of data

Example 1

The table shows the number of species added to the list of endangered and threatened species in the United States during the given years.  Graph a scatter plot using the given data.

Vocab

• Correlations: describes relationships between 2 sets of data

• Positive Correlation: both data sets increase

• Negative Correlation: one set increases while the other decreases

• No Correlation: No relationship

Example 2

Describe the correlation illustrated by the scatter plot.

Example 3

Identify the correlation you would expect to see between each pair of data sets.  Explain.

A. The number of empty seats in a classroom and the number of students seated in the class

B. The number of pets a person owns and the number of books that person read last year.

C. The monthly rainfall and the depth of water in a reservoir

Multiple Choice

Which scatter plot show a positive relationship?

• Graph A

• Graph B

• Graph C

• Graph D

Multiple Choice

What type of correlation does this scatter plot show?

• positive

• negative

• no correlation

• nonlinear association

Multiple Choice

What type of correlation does this graph have?

• Negative

• no association

• positive

Example 4

Choose the scatter plot that best represents the relationship between the number of days since a sunflower seed was planted and the height of the plant.  Explain.

Multiple Choice

Which sentence describes the relationship shown on this scatter plot?

• As the temperature decreases, the visitors increase.

• As the temperature increases, the number of visitors increases.

• As the visitors increase, the temperature decreases.

• No correlation

Vocab

• Trend Line (Line of best fit): Shows correlation between the data sets

Example 5

The scatter plot shows a relationship between the total amount of money collected and the total number of rolls of wrapping paper sold as a school fundraiser.  Based on this relationship, predict how much money will be collected when 175 rolls have been sold.

Multiple Choice

Mrs. Collins made a scatterplot to show the relationship between the number of absences and a student’s final exam score. Based on this scatterplot, a student with 12 absences should get approximately what score on the final exam?

• 60

• 92

• 70

• 76

Multiple Choice

Which scatterplot most likely has a line of best fit represented by y = - 2x + 1

• W
• X
• Y
• Z

Multiple Choice

What type of correlation does this graph have?

• positive

• negative

• none

• all of the above