I need some help with the first part of this problem and solving for OCF

Trying to calculate sensitivity for OCF when change in quantity sold ?

OCF=[(PV)QFC](1t)+T(D)

5 Year project 

initial fixed investment $450,000

Can you help figure out the (?) in this OCF equation: OCF=[(3115)(109,350)202,500][????)+.31(450,000/5)

straightline depreciation to zero over 5 yr. life

zero salvage value

price: $31

variable costs $15

fixed costs: $202,500

quantity sold = 109,350 units

tax rate 31%