Answer:
The rate's aren't equivalent.
Explanation:
If you find a common number of hours between the two expressions such as 24 hours you will see that the pay isn't the same. $24 for 6 hours of work ($4:1hr) can be turned into $96 for 24 hours of work and $36 hours for 8 hours of work ($4.5:1) turns into $108 for 24 hours of work.