I just need proper work shown for this problem. I have the answer down below.

1. January: $126,000; February: $119,000; March: $108,500

Tunes Electronics sells wireless headphones. Sales for the first four months of the year are as follows: January sales: $180,000 February sales: $170,000 March sales: $155,000 April sales: $165,000 Gross profit is estimated to be 30% of sales. Ending inventory should be 25% of the following month's cost of goods sold. What is budgeted cost of goods sold for January, February, and March