Answer :
Final answer:
To calculate the amount of water in a 126 kg person, we use the ratio 60 kg/90 kg from the 90 kg person as the proportional constant. Then, we apply the constant (2/3) to the 126 kg person's weight, resulting in 84 kg of water.
Explanation:
The question pertains to direct proportionality in the context of body water content and the mass of a human body. Given that a 90 kg person contains 60 kg of water, we are to find out how much water is in a 126 kg person. We use the concept of direct proportion where if two values are directly proportional, as one increases, the other does as well at a constant rate.
First, we determine the proportionality constant, k, by using the information given:
- The formula for direct proportion is y = kx, where y is the amount of water, and x is the mass of the person.
- We can find k by plugging in the values from the 90 kg person: 60 kg = k × 90 kg. Therefore, k = 60 kg / 90 kg = 2/3.
- Now we use k to find the amount of water in a 126 kg person: y = (2/3) × 126 kg.
- After calculating, we find y = 84 kg of water in a 126 kg person.
