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.
Profit Margin Ratio. Profit margin ratio is the ratio of the business's gross profit in relation to sales. Using the example above, your net income is $1,500 a month. Divide this figure by the total income of $5,000 a month, and your percentage of income that constitutes profit is 30 percent. This means that the profit margin ratio is 0.30:1, or 30 percent of each dollar earned.