Short answer: 30%
Explanation: To find the percentage increase in the dog's weight, we can use the formula:
Percentage increase = (New weight - Old weight) / Old weight) * 100%
Given:
Old weight = 4 kg
New weight = 5.2 kg
Substituting the values into the formula:
Percentage increase = ((5.2 kg - 4 kg) / 4 kg) * 100%
Percentage increase = (1.2 kg / 4 kg) * 100%
Percentage increase = 0.3 * 100%
Percentage increase = 30%
Therefore, the percentage increase in the dog's weight is 30%.