So an increase from $27,642 to $30,421 is what percentage increase?

And a decline from $30,421 to $28,520 is what percentage decrease?

Can you also give me the formula you used?

1. about 10% increase

2. a decrease of 6.25%

Step-by-step explanation:

1.

work out the difference (2779) between the two numbers you are comparing and then divide the increase (2779) by the original number (27642) and multiply the answer by 100.

2.

work out the difference (1901) between the two numbers you are comparing and then divide the decrease (1901) by the original number (30421) and multiply the answer by 100