Answer:
Ww=84 lb
Explanation:
Proportions
A direct proportion is a relation between variables where their ratio is a constant value. This means that if y and x are proportional, then:
y=k.x
Where k is the constant of proportionality.
The value of k is obtained by using the values of a specific point.
The weight of water Ww in a person's body varies directly as their body weight Wb as follows:
Ww=k.Wb
We are given a 170-lb person contains 119 lb of water. Substituting:
119=k.170
Solving for k:
k=119/170=0.7
The function is:

To find how much water is in the body of a 120-lb person, we substitute Wb=120:

Ww=84 lb