Question

The number of milligrams of a certain medicine a veterinarian gives to a dog varies directly with the weight of the dog. If the veterinarian gives a 30-pound dog Three-fifths milligram of the medicine, which equation relates the weight, w, and the dosage, d?
d = StartFraction 1 Over 50 EndFraction w
d = three-fifths w
d = 18 w
d = 50 w

Answer 1

Direct variation: d = k w. Use w = 30, d = 3/5, so k = (3/5)/30 = 3/150 = 1/50. Thus d = (1/50) w.