# Reject or don't reject a null hypothesis?

• Mar 11th 2013, 10:46 AM
vp1489
Reject or don't reject a null hypothesis?
I need help with a final question on my stats homework. This is how the homework starts out, and I am given a table of data:

The Education Testing Service set out to test the relationship between two versions of an aptitude test.

Given the data, I determined the correlation coefficient to be .9276, and the coefficient of determination to be .8604. Given that this is two-tailed, using the 0.05 level of significance (with degrees of freedom at 5), the critical r value is .754.

From this, I determined that the calculated r value exceeds the critical r value.

My teacher's notes (and this chapter in my book) doesn't talk about a null hypothesis at all, but I have to determine which of these two answers is correct (note-I had 5 answers to choose from, but narrowed it down to these two):

1) "The calculated r value exceeds the critical value and therefore we can reject the null hypothesis and conclude that the correlation coefficient is significantly greater than zero."
2) "The calculated r value exceeds the critical value and therefore we can not reject the null hypothesis and conclude that the correlation coefficient is significantly greater than zero."

I am confused as to how I can determine what the null hypothesis is given that they only stated "The Education Testing Service set out to test the relationship between 2 versions of an aptitude test."

I really appreciate anyone who could explain this to me. It is important to me that I understand this as well! Thank you in advance.
• Mar 12th 2013, 02:09 PM
vp1489
Re: Reject or don't reject a null hypothesis?
Is anyone willing to help me out with this question?

We just learned about a null hypothesis last week, but I don't really understand how a null hypothesis can be formed from "The Education Testing Service set out to test the relationship between two versions of an aptitude test."

Any explanation would be greatly appreciated!

Thank you.