$\backslash$table$[[,$Case $1,$Case $2,$Case $3,$Case $4],[$Sales$,$$$,454,000,$$$,191,000,,,$$$,303,000],[$Variable expenses,,,,$129,880,,,,87,870],[\backslash$table$[[$Fixed expenses$]],,,,66,000,,467,000,,],[$Net operating income $($loss$),$$$,50,440,,,$$$,99,190,$$$,(6,870)],[$Contribution margin ratio $($per$,,36,36,,,,,81,81,,,]]$