In developing the pro forma income statement, we follow four important steps: $1)$ compute other expenses, $2)$ determine a production schedule, $3)$ establish a sales projection, $4)$ determine profit by completing the actual pro forma statement. What is the correct order for these four steps?

$3,2,1,4$

$1,2,3,4$

$4,3,2,1$

$2,1,3,4$