9 out of the 15 runners completed the time trial between 52.0 and 53.9 seconds so 9/15 is the percentage you are trying to find. If you divide 9 by 15 and then multiply the decimal by 100, you will have your percentage.
The answer is 60% because there are 9 people who got in between 52.0 and 53.9 seconds and 15 people total in that chart. We can turn this to a fraction 9/15. When we divide 9 and 15 we get .6 and we multiply that by 100 (percents are out of 100) and we get 60%
