The data below represent commute times (in minutes) and scores on a well-being survey. Complete parts (a) through (d) below. Commute Time (minutes), x 5 20 30 35 60 84 105 Well-Being Index Score, y 69.3 68.1 67.3 67.2 66.0 65.6 64.0 a) Find the least-squares regression line treating the commute time, x, as the explanatory variable and the index score, y, as the response variable.

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's.