Answer:
0.2% of the people had mid allergic reaction.
Step-by-step explanation:
Given that:
Number of people tested for a new shampoo = 9000
Number of people who had allergic reaction = 18
Percent of people = [tex]\frac{People\ who\ have\ reaction}{Total\ number}*100[/tex]
Percent of people = [tex]\frac{18}{9000}*100[/tex]
Percent of people = 0.002 * 100
Percent of people = 0.2%
Hence,
0.2% of the people had mid allergic reaction.