Consider the formula LSAT * xLSAT + GPA * xGPA + C =

Now remember that the LSAT is max 180 and GPA is max 4.
Normalize the scores:
Let nLSAT = LSAT / 180 and LSATw = 180*xLSAT
Let nGPA = GPA / 4 and GPAw = 4 * xGPA
For example, for Duke:
LSAT * 0.021 + GPA * 0.268 + (-1.075) =

or
nLSAT * 3.8 + nGPA * 1 + (-1.075) =

Which instantly tells you that a
marginal increase in your normalized LSAT score is about 4 times more important to a Duke admissions officer than an equivalent increase in your normalized GPA.
Maybe somebody could try it with other schools and see what they get?