A hospital did a ten year study on patients who used its services. one thousand patients were randomly selected and followed over a period of ten years to determine the average number of visits per year. by the end of the year period some of the patients had left the area. identify the problem with the pool

My final challenge question of the day! i have no tests, nothing to do this for, it is simply giving away free points for a you tube video! so 50 free points for answering the most simple question ever! here is the key to getting brainiest for this question. answer in under 50 seconds. you think you can do it. i think you can. here is the question: 1x2= i know! easiest question ever! and yes! if you answer this question, you will be on you so come on and get the free 50 while you can!