Answer:
The decrease in number of allergic reactions is of 0.3333%.
Step-by-step explanation:
Initial percentage:
Nine out of 1500, so the percentage is:
[tex]\frac{9*100}{1500} = \frac{900}{1500} = 0.6[/tex]
Initially: 0.6% of allergic reactions.
Final percentage:
Four out of 1500, so the percentage is:
[tex]\frac{4*100}{1500} = \frac{400}{1500} = 0.2667[/tex]
WIth the improved formula: 0.2667% of allergic reactions.
What is the percent decrease in number of allergic reactions?
0.6% - 0.2667% = 0.3333%
The decrease in number of allergic reactions is of 0.3333%.