Answer:
The percent decrease in number of allergic reactions is 55%
Step-by-step explanation:
Only 4 of them had a mild allergic reaction. What is the percent decrease in number of allergic reactions?
Percent of allergic people= Allergic people/ Total people * 100
= 9/1500* 100
= 0.6 %
IT means that out of 1000 people only 6 persons are allergic to the cream.
New Percent of allergic people= Allergic people/ Total people * 100
= 4/1500* 100
= 0.267 %
It means that out of 1000 people only 2.67 persons are allergic to the new improved cream.
Difference between Percentage = Old Percentage- New Percentage
= 0.6 %- 0.267%
=0.333%
Decrease= 0.333% = 0.333/100
In every thousand people 3.33 people are free of allergic reactions from those 6 allergic people.
Percentage Decrease= Decrease/ Total * 100
= 0.333/ 0.6 *100
= 0.55*100
= 55 %
The percent decrease in number of allergic reactions is 55%
