Calculating a regression equation and other stuff

# Calculating a regression equation and other stuff -...

This preview shows pages 1–2. Sign up to view the full content.

Calculating a regression equation You need the following information: The number in your sample, N The mean of your dependent variable and The mean of your independent variable, Covariance of xy or S yx = Variance of X or Standard deviation of X Variance of Y or Standard deviation of Y If you want to know the strength and direction of the relationship between your variables X and Y, you would calculate a Pearson’s r, or the correlation coefficient . This value ranges from -1 to +1. The closer to 0 the lower the relationship. The + indicates a positive relationship (as X increases, Y increases). The - indicates a negative relationship (as X increases, Y decreases). If you want to know how much of the variation in your dependent variable Y is explained by variation in your independent variable X then you calculate the

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: independent variable X then you calculate the r 2 or the Coefficient of Determination which tells you the % of reduced uncertainty in prediction if you use the regression equation/model that you developed. Note that this is the covariation of xy SQUARED! And that the variations in the denominator are not squared. If you use the standard deviation in the denominators, then you would square them. Also, if you calculate r 2 first and then calculate r by taking the square root, be sure to go back to see if you have a negative covariance and if so then your r should be negative as well. If you use the following table, it will help you calculate all the things you need for all of the above formulas. Calculation table should include: X Y ( ) ( ) 2 ( ) ( ) 2 ( ) ( ) 1 2 3 4...
View Full Document

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern