basic mathematics image
 basic mathematics image

Scatter plots


Scatter plots are used to show relationship between two sets of data by writing them as ordered pairs

To illustrate, let us pretend that you have a business that sells notebooks

Day 1, you sell 10 notebooks

Day 1, you sell 10 notebooks

Day 2, you sell 5 notebooks

Day 3, you sell 15 notebooks

Day 4, you sell 10 notebooks

Day5 , you sell 20 notebooks

Day 6, you sell 15 notebooks

Day 7, you sell 30 notebooks

Day 8, you sell 15 notebooks

Day 9, you sell 25 notebooks

Day 10, you sell 15 notebooks

You can display this situation with ordered pairs as shown below:

(1,10), (2,5), (3,15), (4,10), (5,20), (6,15), (7,30), (8,15), (9, 25), and (10, 15)

Then we can put the ordered pairs on the coordinate system. The resulting graph is called a scatter plot or scatter graph.

Notice how the points are scattered around and everything is located in the first quadrant

scatter-plot-image




Two sets of data can form 3 types of relationships

When y increases as x increases, the two sets of data have a positive correlation

Basically, when you closely examine the graph, you will see that the graph has a tendency to go upward

Example

positive-correlation-image


When y decreases as x increases, the two sets of data have a negative correlation

Basically, when you closely examine the graph, you will see that the graph has a tendency to go downward

Example

negative-correlation-image


When x and y are not related, we say that the two sets of data have no correlation

Example

no-correlation-image






Page copy protected against web site content infringement by Copyscape





worksheets-banner







Copyright © 2008-2015. Basic-mathematics.com. All right reserved

Are you a fan of this site? Support us     Our awards!     Our partners     About me     Disclaimer     Build your website!     Advertise on my site
    Try our free toolbar     Like us on Facebook     Take our survey     Illustrated fractions     Educational math software     Math jobs     Best Teacher Sites Now     Teachers/Students tools     Search math jobs     Algebra ebook     Fraction ebook     Geometric formulas ebook