Susan has just completed her second semester in college. She earned a grade of C in her 3-hour topology course, a grade of B in her 5-hour sociology course, a grade of B in her 4-hour chemistry course, and grade of A in her 2-hour speech writing course. Assuming that A equals 4 points, B equals 3 points, C equals 2 points, D equals 1 point, and F is worth no points, determine Susan's grade-point average for the semester.
Susan's grade point average is ?