Since pay rate for this case is the money earned over time.
Your pay rate will be 117.60 dollars / 14 hours = 8.40 dollars per hour
Ty's pay rate will be 148.50 dollars / 18 hours = 8.25 dollars per hour
Kim's pay rate will be 137.60 dollars / 16 hours = 8.60 dollars per hour
Therefore, the highest pay rate is Kim.
