Helmer's Rockers manufactures two models, Standard and Premium. Weekly demand is estimated to be 109 units of the Standard Model and 70 units of the Premium Model. The following per unit data apply Standard Contribution margin perut $18 Number of machine-hours required 3 6 The contribution per machine hour is $6 for Standard, 54 for Premium $15 for Standard, 518 for Premium 554 for Standard, 144 for Premium $18 for Standard, 24 for Premium