Problem $6$A$-7($Algo$)$ Cost Behavior; High$-$Low Method; Contribution Format Income Statement $[$L$06-10]$

Morrisey & Brown, Limited, of Sydney is a merchandising company that is the sole distributor of a product that is increasing in popularity among Australian consumers. The company's income statements for the three most recent months follow:

$\backslash$table$[[\backslash$table$[[$Morrisey & Br$],[$Income St$],[$For the Three Months$]],\backslash$table$[[$Wn$,$ Limited$],[$tements$],[$Ended September$],[$July$]],\backslash$table$[[30],[$August$]],$September$],[$Sales in units,$4,250,4,750,5,250],[$Sales$,$$$446,250,$$$498,750,$$$551,250$