Body mass index mathematical equations and calculations

Inequalities are useful for when a person wants to demonstrate that there are multiple possible answers to a question, or a range of answers to a particular math question. This example uses body mass index (BMI) as a way of demonstrating how some answers have ranges. The BMI is a rough measure of health based on weight and height. The formula for calculating BMI is as follows: BMI = [W / H2] *703. The following guidelines are suggestive of the relationship between health and weight: 17

To determine the appropriate weight range or interval for individuals in each category, one would solve for W. based on the given height and the numbers at each end of the range, which provides an equivalent equation. To isolate W, one begins with the basic equation BMI = [W / H2] *703. The first step is to divide each side by 703, which yields the following intermediate equation: BMI/703 = [(W / H2) *703]/703, which is simplified to BMI/703 = (W / H2). The next step involves multiplying by the square of height on both sides. (BMI/703) * H2= (W / H2) * H2. Simplified, those results show an equation where W. is isolated, allowing one to solve for weight when given a specific height and BMI: [BMI/703] *H2= W.

At a height of 5'7" (67 inches) and a weight of 140 lbs, the BMI of the individual examined for this paper is found with the following equation. BMI = [140 / 672] *703. The BMI is 21.92. Based upon the BMI information provided, these numbers suggest a BMI that is linked to a higher life span than average. The same height can then be used to examine the weight ranges associated with the different BMI ranges for a person with a height of 67 inches. The first BMI range is: 17

Using set notation to describe the category of people who are probably overweight, one begins by looking at the range provided in the solution: 160 lbs < Probably overweight 160 and w < 192}. In interval notion, the same range would be expressed as X = (160, 192). Because only one measurement, weight, is being considered for this set of solutions, the simplest graph to use is a number line. On a number line, the set could be depicted as follows: