I think I Get it, but Not Sure...
The real numbers? Who knows? Some students get it right and understand the first time; other may take a while. Also important to remember that a C-172 is not B-737 or larger. Actions, procedures and results Will Vary.
If you are a CFI or any grade, when the student masters the procedure with little or no comment from you. In the end, the aircraft does not matter. What matters is to always be prepared and during approach and landing, Always be prepared to modify your plan. Always.