# Which Table of Values Represents the Residual Plot

**Which Table of Values Represents the Residual Plot**

Student:

What is a residue?

Mentor:

Well, a residual is the difference between the measured value and the predicted value of a regression model. It is important to understand residuals because they show how accurate a mathematical function, such as a line, is in representing a prepare of data. To find a residual you must take the predicted value and subtract it from the measured value.

Pupil:

What are the predicted values? How do you observe that?

Mentor:

The line of best fit provides the predicted values for a gear up of data. For example, with the line of all-time fit the predicted value is the value on the line that corresponds to a specific independent value. Take a look at the graph. The y-coordinate values on the line of best fit lucifer the x-values from the data gear up.

At present let’s use the Regression Activeness to calculate a residuum! Starting time, allow’s plot the following four data points: {(1, two) (two, 4) (three, 6) (four, 5)}. The labels 10 and y are used to represent the independent and dependent variables correspondingly on a graph. These given y-values (dependent variables) are the measured values for the specified x-values (independent variables). At present, let’s graph the line of best fit by selecting

*Display line of best fit*

and see where the predicted values lie on the graph.

Student:

Cool! At present I can see what you mean most the predicted and the observed values!

Mentor:

Corking, at present permit’s try to discover the residual for the contained variable, x = i. How would you do this?

Pupil:

Well, I would outset write downwardly the measured value for independent variable x=1, which would be ii since I plotted (ane, 2). At present, I run across that when the 10-value is ane, the y-value on the line of best fit is approximately 2.half dozen. Then, to find the residual I would subtract the predicted value from the measured value so for 10-value 1 the residual would exist ii – 2.half-dozen = -0.6.

Mentor:

That is right! The residual of the independent variable x=i is -0.6. If you lot are having problem remembering which value to decrease from which you lot can recollect well-nigh it this way: you are trying to see how far off the predicted value is from the actual value so you would desire to take the actual value and subtract the predicted value to see how far off the predicted value is from the actual value. Sometimes the residual will be positive and sometimes it volition exist negative. When practicing finding residuals you can besides utilise the Regression Action and select

*testify residuals*

to compare your findings.

Student:

Cool! Under the cavalcade X the value 1 corresponds with the number -0.6 under the cavalcade

*line of best fit*. The residual is -0.vi for x=1, so practise the numbers in the

*line of best fit*

column represent the residuals for each x-value?

Mentor:

Yes. Too, the Residual Plot graphs the residuals every bit the y-values with the corresponding x-values. The Residue Plot gives you a visual mode of representing residuals of independent and dependent variables.

Student:

This is really helpful – now I know how to find residuals!

## Which Table of Values Represents the Residual Plot

Source: http://www.shodor.org/interactivate/discussions/FindingResiduals/