ZZ Company produces and sells four products. Information about these products for 2019, the most recent year, appears below: selling price per unit variable costs per unit number of units sold Product A $18 $ 6 22,000 Product B $16 $ 5 36,000 selling price per unit variable costs per unit number of units sold Product C $17 $13 15,000 Product D $13 $ 7 20,000 ZZ Company reported total fixed costs of $540,000 in 2019. Calculate zz Company's degree of operating leverage for 2019