Stats against simple data - but need help still

This i my first post...I'm struggling at the moment with a course I'm taking and could use some help. So, here goes!

Here are the details:

Hypothesis: A score on the LSAT below 145 will yield a cumulative GPA of less than a 3.0 in the first year of Law School.

Null: The LSAT score has no affect on a student's first semester GPA

Independent Variable: LSAT Score
Dependent Variable: GPA at the end of the first semester.

I have 2 samples of 100 each. I'm not (and cannot) give the full dataset but here is basically what the data looks like in my Excel spreadsheet:

LSAT Score GPA after 1 semester
130 2.78
156 3.00
155 2.96
141 3.22
140 2.56

This may sound like a dumb question, but how, based on my two samples, do I find out if my hypothesis is true? That students who score less than a 450 on the LSAT will have a GPA lower than a 3.0 after the first semester of law school. I've rad about Chi Square and T-tests and ANOVA etc but I cannot link those tests to proving my hypothesis (or rejecting the null).

Thanks in advance!!!!
As this is trying to say something between two things, we might think of this as ' how they are related, are they highly correlated?' One thought will be to try simple regression analysis. GPA=a+b*LSAT, then

H0: b=0

It's possible to try other models, which should desired to be a good conceptualization of the real phenomenon.