The range of healthy weight for adults is usually expressed in terms of the body mass index (BMI), defined, in SI units, as
where W is the weight (actually, the mass) of the person in kg and H is the height in m, and the range of healthy weight is 19 ≤BMI ≥ 25. Convert the previous formula to English units such that the weight is in pounds and the height in inches. Also, calculate your own BMI, and if it is not in the healthy range, determine how many pounds (or kg) you need to gain or lose to be fit.