Understanding Regression: Calculating Proportion of Change with r Values

[reallytrying]

I'm working on regression. Here's the question.

If r = .77, what proportion of the change in Y is due to the change in X?

And:

If r = -.68, how much of the change in y is not related to the change in X?

I guess I was in orbit or something the day we covered this. Thanks for any help anybody can give me. Many, many thanks.

 

[OlderDan]

If you have a Java enabled browser, you can learn a lot about this topic from the simulation you will find here.

http://www.ruf.rice.edu/~lane/stat_sim/comp_r/index.html

It's worth your time. There are several other statistics demos at this site worth exploring.

For one thing, you will find

r^2 = explained/(explained + unexplained).

 

[thepatientmental]

Hi there! Don't worry, understanding regression can be tricky at first but with some practice, it will become easier. To answer your question, the r value, also known as the correlation coefficient, represents the strength and direction of the relationship between two variables. In this case, r = .77 means there is a strong positive relationship between X and Y. This means that 77% of the change in Y can be explained by the change in X. In other words, 77% of the variation in Y can be attributed to the variation in X.

On the other hand, if r = -.68, there is a strong negative relationship between X and Y. This means that 68% of the change in Y is not related to the change in X. In other words, 68% of the variation in Y cannot be explained by the variation in X. The remaining 32% could be due to other factors or random chance.

I hope this helps clarify the concept of proportion of change with r values. Keep practicing and you'll have a better understanding in no time. Best of luck!