I need to scale some tests. The highest grade is a 90 and the lowest is a 20. I want to scale them so that the lowest is a 60 and the highest is a 100. How do I make an equation that will do this?
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Let's call the are the old scores and the are the new scores.
We can make a linear relationship with the following co-ordinates (old , new) = and the equation will be in the form where
now using to find the value for
To scale future scores
Thank you very much, very clear and helpful.
I should remember how to do that. I'm a university graduate. Darn.
Last edited by mr fantastic; Dec 28th 2010 at 07:06 PM.
Reason: m --> r
The formula I am about to give you is not perfect, but I think it is decent.
Let n=New Grade
Let o=Old Grade
The 20 will end up with a 60, but the 90 will end up with a 95. Sorry if it isn't what you're looking for.
EDIT: too late
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