To find the percent of bags of tortilla chips that were fat free, we need to divide the number of fat-free bags by the total number of bags and multiply the result by 100%.
The percentage of bags that were fat-free is:
(2173 fat-free bags / 3481 total bags) * 100% = 62.72%
Rounded to the nearest percent, the percentage of bags that were fat-free is 63%.