Part $2/3$ Problem $20-3($Static$)$ Change in inventory costing methods; comparative income statements $[$LO$20-2,20-3]$

$[$The following information applies to the questions displayed below.$]$

Shown below are net income amounts as they would be determined by Roberti Steel Company by each of three different inventory costing methods $($$ in thousands$).$

$\backslash$table$[[,$FIFO,Average Cost,LIFO$],[$Pre$-2023,$$$2,800,$$$2,540,$$$2,280$ Please double check all work, and answer problems completely and clearly. Will upvote if all parts are accurately completed thanks!