quality control

hi, i was wondering what kind of control chart would i use (r and x, or P or C chart) if i want to determine whether employees are offering customer warranty on purchase at different hours of the day - varing the number of customer that wil be at the store per hour.


the question is what chart would i use to determine whether the customer are still being asked if they want the warranty or not for the following day (the answer is a 'yes' or "no" on the customer being offered warranty) and how would i determine whether or not they are base on the chart.
Thank you

Thread moved to charting forum & poster PM'd to read rules