While it might be tempting to use Desmos to perform a regression on the table of values given in the problem, that would actually be the wrong move, since you are looking for the y-intercept of f(x) not g(x).  We will use Desmos to perform a regression, but first let's see how to construct f(x) by hand.  Duration: 16:00

As an extension to the previous video, let's examine the graph of g(x) as a ratio of two linear functions.  This will be a nice sneak preview of some advanced mathematics that you aren't ordinarily scheduled to learn until late into the Algebra 2 course.  Duration: 9:46