y = 0.0015 x^3.1239
For a power function
there are only two parameters.
So if we know two points on the graph we can find a and p, and we'll know the function. However, it's not easy at this point of the course to solve for a and p.
Sometimes we have a pretty good idea what p should be.
If we think we already know p, then we need only one point to evaluate a.
But we check several points and see if our a values are consistent.
That is, if we use several points, and evaluate a separately for each point, then if our a values are all about the same, we know our p value is pretty good.