Patterson parkas company's sale revenue is $30 per unit,variable costs are $19.50 per unit, and fixed costs are $147,000. a-compute Patterson's contribution margin per unit and contribution margin ratio b-determine the number of units Patterson must sell to break even c-determine the sales revenue required to earn (pretax) income equal to 20% of revenue. d-how many units must Patterson sell to generate an after tax profit of $109,200 if the tax rate is 35% e-Patterson is considering increasing its advertising expenses by $38,500.How much of an increase in sales units is necessary from expanded advertising to justify this expenditure(generate an incremental contribution margin of $38,500)