Drexel dragonThe Math ForumDonate to the Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.

Math Forum » Discussions » Courses » ap-stat

Topic: [ap-stat] explaining r^2
Replies: 1   Last Post: Nov 1, 2011 2:26 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Erin Long

Posts: 26
Registered: 9/29/11
[ap-stat] explaining r^2
Posted: Oct 31, 2011 12:19 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Based on the given Explanatory and Response Variables, I am trying to determine how to grade the explanation of r^2 on an exam. Here a few responses I received...

Explanatory variable = number of teaspoons of weed killer
Response Var = percent of weeds killed
r^2 = .972

1) 97.2% of the variation in the percent of weeds killed can be explained by the variation in the amount of weed killer used.

2) Approximately 97.2% of the percent of weeds killed can be explained by the strength of the weed killers on the field.

3) 97.2% of the variation in the percent of weeds killed can be explained by the linear relationship between the amount of weed killer used and the percent of weeds killed.

I taught the students to use #3, but I wasn't sure if #s 1 and 2 are acceptable as well.

Thanks in advance for the feedback!

Frequently asked questions(FAQ) http://web.me.com/mrmathman/MrMathMan/FAQ.html
List Archives from 1994: http://mathforum.org/kb/forum.jspa?forumID=67
To search the list archives for previous posts go to
To unsubscribe click here:
To change your subscription address or other settings click here:

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2015. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.