Scatter Plots (10)

Use scatter plots to investigate and comment on relationships between two numerical variables (ACMSP251)

LO: To investigate and comment on scatter plots

Know:

  • How to use data to create a scatter plot
  • How to label a scatter plot graph

Understand:
That scatter plots can represent a relationship between two factors (variables)
Do:

  • I can use scatter plots to investigate and comment on relationships between two numerical variables.

Visual Representations

Scatter Plots

Scatter plots are an easy way of organizing data from two categories into 1 graph.

Basically it’s identifying data from 2 categories then placing a dot (point) at where the data points correspond.

Relationships in Scatter Plots

Sometimes we can draw a generalization from the data that we see in a scatter plot.

If the data points are moving (trending) towards the upper right then it can be considered to have a positive correlation. Both variables are increasing at a similar rate.

If the data points are moving (trending) towards the bottom right then the data can be considered to have a negative correlation. Both variables are decreasing at a similar rate.

If the data points don’t present a trend (all over the place) then the data can be considered to have no correlation.

Positive Correlation

This is an example of a positive correlation, as students spent more time studying, the student grades also improved.

Negative Correlation

This is an example of a negative correlation, as students spent more time training, the time it took to run 100m decreased

No Correlation

This is an example of no correlation, the colours in a rainbow have no relationship to the shoe size.

Creating a Scatter Plot Videos

Correlation Videos

Practise Questions

My Maths 9

Exercise 8F pg. 395 Q. 10-12

My Maths 10/10A

Exercise 10E pg. 507 Q. 1-5

Next Lesson – Standard Deviation