I started off with the approximate number of hospitals in a state (taking into consideration which states would have more no. (ones with metropolitan cities) and which states would have a scarce number. Then i proceeded to estimate the number of patients requiring x-ray done in one day and multiplied it by 365. I similarly proceeded with estimating the number of path labs that provide x-ray facilities. I estimated the area of one x-ray film and multiplied it with the number of patients in a year.