ZTL Ltd produces three products. Cost, price, and volume data is shown below: Total Fixed costs Tax rate $2,400 40% Picture Candle CD Holders Holders Holders Normal volume 300 150 200 Price per unit $5 $7 $10 Variable cost per $2 $3 $ 4 unit The weighted average contribution margin ratio, rounded to the nearest whole percent, is: Select one: a. 62% O b. 60% c. 57% d. Some other number e. 59%