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.
as an example of a profit margin calculation suppose firm a made a profit of $ 10 on the sale of a $ 100 television set dividing the dollar amount of earnings by the product cost that firm s profit margin would be 10 or 10 percent meaning that each dollar of sales generated an average of ten cents of profitividing the dollar amount of earnings by the product cost that firm s profit margin would be 10 or 10 percent meaning that each dollar of sales generated an average of ten cents of profit