Angora Creations Company manufactures wool sweaters. Costs incurred in making $9,000$ sweaters in September included $\backslash (\backslash$$ $39,150\backslash )$ of fixed manufacturing overhead. The total absorption cost per sweater was $\backslash (\backslash$$ $11\mathrm{.}75\backslash ).$ Required: a$.$ Calculate the variable cost per sweater. b$.$ The ending inventory of sweaters was $1,700$ units lower at the end of the month than at the beginning of the month. By how much and in what direction $($higher or lower$)$ would cost of goods sold for the month of September be different under variable costing than under absorption costing? c$.$ Express the sweater cost in a cost formula. Complete this question by entering your answers in the tabs below. Express the sweater cost in a cost formula. Note: Round your intermediate calculations and "Variable cost" to $2$ decimal places.