German for X rays where 'X'  means   'unknown'. In Europe X-rays are known as Roentgen rays.    X-Radiation is a form of electromagnetic radiation having a  wavelength of   0.01 to 10 nanometers.NS2: The name x-ray was applied to radiation in the same frequency as gamma radiation but which originate from a man-made source.
wikiHow to Calculate Gross Profit Margin. Gross profit is a fairly simple comparison of the cost of the goods your company sells to the income derived from those goods. Gross profit margin is the ratio of gross profit to total revenue expressed as a percentage.
Step 1. Subtract the expenses from the revenue to find your profit on your sales. For example, if you have $575,000 in sales and $485,000 in expenses, your profit equals $90,000. Step 2. Divide the profit by the sales to find the portion of each dollar you keep as profit.tep 1. Subtract the expenses from the revenue to find your profit on your sales. For example, if you have $575,000 in sales and $485,000 in expenses, your profit equals $90,000. Step 2. Divide the profit by the sales to find the portion of each dollar you keep as profit.