1 Onset of sleep from time the lights were turned off; this is called  sleep onset latency  and normally is less than 20 minutes. ( 2 Note that determining sleep and awake is based solely on the EEG. Patients sometimes feel they were awake when the EEG shows they were sleeping.
The direct cost margin is calculated by taking the difference between the revenue generated by the sale of goods or services and the sum of all direct costs associated with the production of those goods, divided by the total revenue.
Calculate the contribution margin per unit by subtracting the variable cost per unit from the sales price per unit. For example, if a small company's product sells for $60 per unit with variable costs per unit of $20, the contribution margin per unit would be $40.lug the TFC and contribution margin figures into the formula: BEP (in units) = TFC/contribution margin per unit. In this example, the small company's BEP would equal $40,000/$40, or 1,000 units. Determine the break-even point from the calculation.