Originally Posted by Quantum2003
I would be shocked if the answer were not Y = 1.5X + 2. The y-intercept has to be 2 if you want to model the situation as a linear relationship. Because of the wording in the first sentence of the problem, I just assumed that the increase is 1.5 miles each week even though he jogs every day.

Except that the problem clearly stated they wanted X to equal the week number, and Y to equal the number of miles run. The function y = 1.5x + 2 does not describe that relationship.

The linear equation y = 2 + 1.5(x - 1) does have a Y intercept of 0.5, so that's probably the answer the teacher is looking for. It's just that, in the context of the question, it's nonsensical.