In order to divide currency by duration, you will need to convert them to numeric values first. You will also need to make sure to avoid division by zero. For example: If(($BudgetedHours / Hours(1) > 0, ($C_SalesAmount / Currency(1)) / ($BudgetedHours / Hours(1)), 0)
As for the report, please try different summary types to see if any perform the calculation you need.
I hope this helps.