Answer:
Step-by-step explanation:
A direct variation equation is of the form
y = kx,
where, in words, it reads "y varies directly with x" or "y varies directly as x". In order to use this as a model, we have to have enough information to solve for k, the constant of variation. The constant of variation is kind of like the slope in a straight line. It rises or falls at a steady level; it is the rate of change.
We have that a vet gives a dose of three-fifths mg to a 30 pound dog. If the dose varies directly with the weight of the dog, then our equation is
d = kw and we need to find k in order to have the model for dosing the animals.
[tex]\frac{3}{5} =k(30)[/tex]
Divide both sides by 1/30 to get k alone.
[tex](\frac{1}{30})(\frac{3}{5})=k[/tex] and
[tex]k=\frac{1}{50}[/tex]
Our model then is
[tex]d=\frac{1}{50}w[/tex]
This means that for every pound of weight, the dog will get one-fiftieth of a mg of medicine.
