PCO stands for Potential Change Order (construction management). Suggest new definition. This definition appears somewhat frequently and is found in the following Acronym Finder categories: 1  Business, finance, etc.
Quick Answer. The Roman numeral XIX is the number 19. X is the number 10, and I is the number one. When a lower number is placed in front of a larger number, it indicates subtraction; IX is the same as 10 minus one, which equals nine. The Ancient Romans used different letters to represent numbers.
Roman numerals XL. The roman numeral XL corresponds to the arabic number 40. XL = 40. We hope you have found this information useful. Please, consider to like this site on Facebook. How to read and how to write XL. Symbols are written and read from left to right, from highest to lowest.