Formula for Report Designer Union Rate

I am trying to correct a formula on one of our Certified Reports (in Report Designer) to where I need to be able to calculate an hourly fringe rate based off their fringes and Union Class/Certified Class.  I can correctly calculate the total fringe amount but when there is an instance that an employee has 2 classes within a week I am unable to get the hourly rate correct.  It is pulling in the total hours for the week into the formula to divide by and I can't seem to figure out if it is even possible to break it down by the hours for each class.