Final answer:
The dog's weight increased by 25% over the year, calculated by determining the absolute increase (16 pounds) and then dividing by the original weight (64 pounds) and multiplying by 100.
Step-by-step explanation:
To calculate the percentage increase in the dog's weight from 64 pounds to 80 pounds, you first need to determine the absolute increase in weight. This is done by subtracting the original weight from the new weight. So, the increase is 80 pounds - 64 pounds = 16 pounds. Next, to find the percentage increase, you divide the absolute increase by the original weight and then multiply by 100 to get the percentage. The formula looks like this:
Percentage Increase = (Absolute Increase / Original Weight) × 100
Putting the values into the formula we get:
Percentage Increase = (16 / 64) × 100
Percentage Increase = 0.25 × 100
Percentage Increase = 25%
Therefore, the dog's weight increased by 25% over the year.