With your current domain model that would be quite hard. First your CourseCredit is a string instead of a decimal. Second problem is that the reference between those entities a one to multiple association. So how do I know which Studentfinancialinfo I should adjust?
What you could do after you changed the CourseCredit to a decimal is make an on change microflow that just creates a Studenfinancialinfo object, set the reference to Course and calculate the Bills value (which is also by the way a string instead of a decimal) change the attribute and commit all the objects.
Hope this helps a bit, but I would advice you to follow some learning paths in the academy.