Answer:
99.4%
Explanation:
Total number of people tested = 2500
People who had allergic reaction = 15
People who didn't have allergic reaction = 2500 - 15 = 2485
Percentage = Part of a whole / The whole
=> 2485 / 2500
=> 497 / 500
=> .994
To convert a decimal into percent:
=> We need to make the decimal point move 2 times to the right
=> .994
=> 99.4%
So, 99.4% of the people who were tested, didn't have an allergic reaction.