Are they true or false please?

3.The breakeven point in sales is the fixed cost divided by the contribution margin per unit.

4.The margin of safety equal actual sales-breakeven sales

5.machine hours can be used as an allocation base for calculating the

pre determined rate

6.An unfavorable labor rate variance can occur if workers with high hourly wage rates are assigned to work on products with standards that assume workers have low hourly wage rates.

7.The variable overhead efficiency variance measures how efficiently variable manufacturing overhead resources were used.