Process costing- joint product

Two products (J and K) are created from a process. There are no opening inventory of finished goods. Joint product costs were $630,000.

Product Closing inventory (units) Sales (units)
J 1000 11,000
k 4000 24,000

Using physical basis for apportionment of joint production costs, what was the value of closing inventory of J?

i have worked as follows But didnt get the answer:

12/24* $630000= $270000 of J

270000/12000= $22.5 per unit c

closing inventory J= 1000*$22.5 = $22500

[please help me, where does the fault lies?]