1.7 How many hours do I need to spend on the class.?
CA Ed Code, Title 5 §55002 - the Carnegie Unit Rule

Guideline for Section 55002.5
In this section, the basic unit of college credit is defined to avoid reference to specific term lengths (previously described in terms of hours/week over a 16-week term). A minimum of 48 hours on the semester system (or 33 hours on the quarter system) of lecture, study, lab work is required for one unit of credit regardless of term length. The section establishes the minimum expected time on task (lecture, study, and or lab work) that is necessary to award one unit of credit. In practice, the number of hours varies among institutions, but is generally within the range of 48-54 hours per unit for colleges on the semester system. For each hour of lecture, it is assumed that students will be required to spend an additional two hours of study outside of class. The number of units awarded for laboratory courses is generally based entirely on the number of hours of laboratory work, presuming that students complete most required work in class.

To determine the estimated number of hours a student will spend on the course per week, divide the total hours by the number of weeks in your term.

For example, a 3 unit online class requiring 144 hours of work will, taught in a 15-week semester term, require roughly 10 hours of student work per week (144/15).