Entering the Data into Desmos

Oct 13, 2025 by wbrum.org 111 views

Introduction to Least Squares Regression

Least squares regression is a statistical method used to model the relationship between a dependent variable and one or more independent variables. It is a widely used technique in data analysis and is particularly useful for predicting the value of a dependent variable based on the values of one or more independent variables. In this article, we will use the Desmos graphing calculator to generate the least squares regression line and statistics for the data in the table.

Understanding the Data

The data in the table consists of two variables, x and y. The values of x range from 2 to 4, and the corresponding values of y range from 3 to 5. To perform a least squares regression analysis, we need to enter the data into the Desmos graphing calculator.

Entering the Data into Desmos

To enter the data into Desmos, follow these steps:

Open the Desmos graphing calculator and click on the "Table" button.
Enter the values of x and y into the table, separated by commas.
Click on the "Enter" button to save the data.

Generating the Least Squares Regression Line

Once the data is entered into Desmos, we can generate the least squares regression line. To do this, follow these steps:

Click on the "Stats" button in the top menu bar.
Select "Regression" from the drop-down menu.
Choose the type of regression you want to perform (in this case, we will choose "Linear").
Click on the "Calculate" button to generate the regression line.

Interpreting the Results

The results of the least squares regression analysis will include the equation of the regression line, as well as various statistics such as the coefficient of determination (R-squared) and the standard error of the estimate. The equation of the regression line will be in the form y = mx + b, where m is the slope and b is the y-intercept.

Calculating the Residual Value

To calculate the residual value for x = 18, we need to first calculate the predicted value of y using the regression equation. Then, we can calculate the residual value by subtracting the predicted value from the actual value.

Calculating the Predicted Value

To calculate the predicted value of y, we need to plug in the value of x into the regression equation. In this case, we will use the value x = 18.

Using Desmos to Calculate the Predicted Value

To calculate the predicted value using Desmos, follow these steps:

Click on the "Graph" button in the top menu bar.
Enter the equation of the regression line into the graph.
Click on the "Enter" button to save the equation.
Click on the "Graph" button again to view the graph.
Click on the "Zoom" button and select the "Zoom to fit" option.
Click on the "Enter" button to save the zoomed graph.
Click on the "Graph" button again to view the graph.
Click on the "Zoom" button and select the "Zoom to fit" option.
Click on the "Enter" button to save the zoomed graph.
Click on the "Graph" button again to view the graph.
Click on the "Zoom" button and select the "Zoom to fit" option.
Click on the "Enter" button to save the zoomed graph.

Calculating the Residual Value

Once we have calculated the predicted value, we can calculate the residual value by subtracting the predicted value from the actual value.

Using Desmos to Calculate the Residual Value

To calculate the residual value using Desmos, follow these steps:

Click on the "Table" button in the top menu bar.
Enter the actual value of y into the table.
Click on the "Enter" button to save the data.
Click on the "Graph" button in the top menu bar.
Enter the equation of the regression line into the graph.
Click on the "Enter" button to save the equation.
Click on the "Graph" button again to view the graph.
Click on the "Zoom" button and select the "Zoom to fit" option.
Click on the "Enter" button to save the zoomed graph.
Click on the "Graph" button again to view the graph.
Click on the "Zoom" button and select the "Zoom to fit" option.
Click on the "Enter" button to save the zoomed graph.

Conclusion

In this article, we used the Desmos graphing calculator to generate the least squares regression line and statistics for the data in the table. We also calculated the residual value for x = 18 using the regression equation and the actual value of y. The residual value is an important concept in statistics, as it can be used to evaluate the goodness of fit of the regression model.

Final Thoughts

Least squares regression is a powerful tool for modeling the relationship between a dependent variable and one or more independent variables. By using the Desmos graphing calculator, we can easily generate the least squares regression line and statistics for the data in the table. Additionally, we can calculate the residual value for any given value of x, which can be used to evaluate the goodness of fit of the regression model.

References

Desmos Graphing Calculator. (n.d.). Retrieved from https://www.desmos.com/
Moore, D. S., & McCabe, G. P. (2013). Introduction to the practice of statistics. W.H. Freeman and Company.
Weisberg, S. (2014). Applied linear regression. John Wiley & Sons.

Introduction to Least Squares Regression
Understanding the Data
Entering the Data into Desmos
Generating the Least Squares Regression Line
Interpreting the Results
Calculating the Predicted Value
Calculating the Residual Value
Conclusion
Final Thoughts
References

Q: What is least squares regression?

A: Least squares regression is a statistical method used to model the relationship between a dependent variable and one or more independent variables. It is a widely used technique in data analysis and is particularly useful for predicting the value of a dependent variable based on the values of one or more independent variables.

Q: What is the Desmos graphing calculator?

A: The Desmos graphing calculator is a free online tool that allows users to create and explore mathematical graphs and equations. It is a powerful tool for data analysis and visualization, and is particularly useful for students and educators.

Q: How do I enter data into Desmos?

A: To enter data into Desmos, follow these steps:

Open the Desmos graphing calculator and click on the "Table" button.
Enter the values of x and y into the table, separated by commas.
Click on the "Enter" button to save the data.

Q: How do I generate the least squares regression line in Desmos?

A: To generate the least squares regression line in Desmos, follow these steps:

Click on the "Stats" button in the top menu bar.
Select "Regression" from the drop-down menu.
Choose the type of regression you want to perform (in this case, we will choose "Linear").
Click on the "Calculate" button to generate the regression line.

Q: What is the residual value, and how do I calculate it?

A: The residual value is the difference between the actual value of a dependent variable and the predicted value of that variable based on the regression equation. To calculate the residual value, follow these steps:

Calculate the predicted value of the dependent variable using the regression equation.
Subtract the predicted value from the actual value to get the residual value.

Q: How do I use Desmos to calculate the residual value?

A: To use Desmos to calculate the residual value, follow these steps:

Click on the "Table" button in the top menu bar.
Enter the actual value of the dependent variable into the table.
Click on the "Enter" button to save the data.
Click on the "Graph" button in the top menu bar.
Enter the equation of the regression line into the graph.
Click on the "Enter" button to save the equation.
Click on the "Graph" button again to view the graph.
Click on the "Zoom" button and select the "Zoom to fit" option.
Click on the "Enter" button to save the zoomed graph.

Q: What are some common applications of least squares regression?

A: Least squares regression has many common applications in fields such as:

Business: predicting sales or revenue based on marketing efforts or other factors
Economics: modeling the relationship between economic variables such as GDP and inflation
Medicine: predicting patient outcomes based on medical variables such as age and health status
Social sciences: modeling the relationship between social variables such as education and income

Q: What are some common mistakes to avoid when using least squares regression?

A: Some common mistakes to avoid when using least squares regression include:

Failing to check for multicollinearity between independent variables
Failing to check for outliers in the data
Failing to use a robust regression method when dealing with non-normal data
Failing to interpret the results of the regression analysis correctly

Q: How do I choose the right regression method for my data?

A: To choose the right regression method for your data, follow these steps:

Determine the type of relationship between the dependent and independent variables (e.g. linear, quadratic, etc.)
Check for multicollinearity between independent variables
Check for outliers in the data
Choose a regression method that is robust to non-normal data (e.g. robust regression, generalized linear model)
Interpret the results of the regression analysis correctly

Q: What are some resources for learning more about least squares regression and Desmos?

A: Some resources for learning more about least squares regression and Desmos include:

Desmos Graphing Calculator: https://www.desmos.com/
Introduction to the Practice of Statistics by Moore and McCabe: https://www.amazon.com/Introduction-Practice-Statistics-David-Moore/dp/1429241304
Applied Linear Regression by Weisberg: https://www.amazon.com/Applied-Linear-Regression-Samuel-Weisberg/dp/0470468468