Answer:
we are missing Troy's production possibilities frontier, but we can make one up that can serve as an example:
Troy's total production:
bolts Δ in bolts wing nuts Δ in wing nuts
500 200 1,900 -300
700 200 1,600 -300
900 200 1,300 -300
1,100 200 1,000 -300
1,300 200 700 -300
1,500 200 400 -300
Troy's opportunity cost of producing 1 bolt is 300 wing nuts /200 bolts = 1.5 wing nuts.
If Troy increases the production of bolts by 1,300 - 900 = 400 units, then the trade off will be 400 x 1.5 = 600 wing nuts.
Your numbers are probably different, but you can adjust them using the same formula.