How to solve with explanation step by step for required $1-15$

Oslo Company prepared the following contribution format income statement based on a sales volume of $1,000$ units $($the relevant range of production is $500$ units to $1,500$ units$)$:

LO$6-1,$

LO$6-3,$

LO$6-4,$

LO$6-5$

LO$6-6,$

LO$6-7$

LO$6-8$

$\backslash$table$[[$Sales$,$$$20,000$