Definition of a Credit Hour
From the University Catalog:
Study leading to one semester credit represents an investment of time by the average student of not fewer than 42 hours. Included in this time is 770 instructional minutes (class time) plus an out-of-class investment of time of 28 hours for such activities as tutorials, recitations, study time and preparation for participation in class, or a demonstration. In a course with a supervised laboratory or studio, some or all of the required 42 hours can be fulfilled by the participation of the student in these activities.