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.
Factor in your gross profit margin. In an alternative to keystone pricing, you may set a desired gross profit margin or percentage to calculate your retail pricing. If your stated gross profit margin is 40 percent, you would take the wholesale price per unit and multiply it by .40, or 40 percent.Next, add this calculation to the wholesale price per unit. For example, a unit with a wholesale cost of $1.00 would retail for $1.40.f your stated gross profit margin is 40 percent, you would take the wholesale price per unit and multiply it by .40, or 40 percent. Next, add this calculation to the wholesale price per unit.