Final answer:
To calculate the percent of change, subtract the original value from the new value, divide the difference by the original value, and multiply by 100.
Step-by-step explanation:
To calculate the percent of change, you need to find the difference between the new value and the original value, and then divide it by the original value. Finally, multiply the result by 100 to express it as a percentage.
In this case, the original value is 25 and the new value is 21.5. The difference between these two values is 25 - 21.5 = 3.5. Dividing 3.5 by 25 gives us 0.14. Finally, multiplying it by 100 gives us 14%.
Therefore, the percent of change is 14%.