Chapter 4 v Define Objectives ratio and proportion

Chapter 4 v Define Objectives ratio and proportion v Locate and decipher ratios in common health applications such as drug labels v Determine if two ratios are a proportion v Simplify ratios and complex ratios v Apply ratio definitions to express unit rates v Solve for x or an unknown in a proportion v Apply proportions to nutrition labels

Ratio & Proportion Pages 94 - 110

Page 103 v Ratio Overview is a way to show a relationship between two items. Ratios simply help us compare two items, objects, or amounts. v. We are always counting and comparing items in our daily lives; hours at work versus hours away from work, number of yogurts we have eaten versus the number of yogurts still in the refrigerator, and so on. v Proportion compares two equal ratios in a mathematical equation.

v. A Ratio Page 105 ratio is used to show a relationship between two numbers. These numbers are separated by a colon (: ) as in 3: 4. Ratios may be presented in three formats that provide the setup for solving proportions. a. 3: 4 b. 3 is to 4 c. ¾ v Ratios are always reduced to their lowest form.

Page 107 Ratios in Health Care v Drug labels are another place that ratios may be seen in health care. Careful reading of the drug label will help locate the dosage of medication per tablet or per amount of solution. Notice that each label uses a specific language indicating a ratio. v Another example of ratio in health care comes from dealing with insurance coverage. There is something called a medical loss ratio, which is used in managed care to measure medical costs as a percentage of premium revenues or income.

Page 109 Proportion v Proportions can be applied to almost every health care profession in one way or another. v Proportions are two or more equivalent ratios or fractions in which the terms of the first ratio/fraction have the same part-to-whole relationship as the second ratio/fraction. v To test two ratios to see if they are equivalent cross multiply.

Page 110 Solving for x v The ratio and proportion method of solving for x is done in two steps. 1. Set the ratios up like fractions. If units of measure such as inches & feet are given, place inches across from inches & feet across from feet. Then cross multiply. 2. Divide the answer from step 1 by the remaining number. The quotient is the answer to x.

Pages 115 – 116 Word Problems Using Proportions v When solving word problems involving proportions, following these two basic steps: 1. Set the problem up so that the same type of elements are directly across from each another. 2. Multiply the diagonal numbers. 3. Divide the answer from step 2 by the remaining number in the problem.

Pages 117 – 118 Solving for x in More Complex Problems Using Proportion v Decimals and fractions may appear in your proportion problems. Although the numbers may be visually distracting, the very same principles apply when solving these proportions. 1. Set the problem up so that the same type of elements are directly across from each another. Cross multiply. 2. Divide to find the missing value.

Pages 119 – 120 Nutritional Application of Proportions v Carbohydrates, fats, & protein provide fuel factors for our bodies. These factors are easily applied by using proportions to solve for the unknown. • • • Carbohydrates → 4 calories per 1 gram Fats → 9 calories per 1 gram Proteins → 4 calories per 1 gram

Page 120 Practice with Food Labels v Knowing how to read food labels important because patients often need to limit their salt, sugar, and fat intake to help ensure good health. v Proportion is useful in figuring out the amounts of these ingredients when portioning – increasing or decreasing portions.