A manufacturer began operations on April $1$ and reports the information below. All jobs are sold for $20\%$ above cost.

Job number Manufacturing costs Job Status at May $31$

April May

$1$ $ $840$ $ $2,160$ Completed and sold during May

$26901,880$ In process

$31,2402,670$ Completed but not sold

$4515440$ Completed and sold during May

$5-3,640$ In process

Compute the May $31$ balance in $($a$)$ Work in Process Inventory and $($b$)$ Finished Goods Inventory.

Compute gross profit for May.