A regression analysis explores the relationship between students' study time (X) and students' grades (Y). The analysis establishes that a student with zero study time is expected to score 40 on the test. The data reveal an average study time of 4 hours and an average test score of 60. For every hour of studies, a student test score is expected to increase by how much? Question 39 options: a) 8 b) 50 c) 0.6 d) 5 e) None of the above