How do we use ratios and proportions in everyday life?

In everyday life, we often encounter situations where ratios and proportions are used to compare quantities or determine unknown values. Here are some examples of how we can use ratios and proportions:
1. Cooking: When following a recipe, we often need to adjust the quantities of ingredients based on the number of servings we want to prepare. Ratios and proportions help us scale the recipe accordingly. For example, if a recipe calls for $2$ cups of flour for $4$ servings and we want to make $8$ servings, we can use the proportion $\frac{x}{2}=\frac{8}{4}$ to find that we need $x=4$ cups of flour.
2. Financial Planning: Ratios and proportions are essential in managing personal finances. For instance, when budgeting, we can allocate a certain percentage of our income to different expenses, such as housing, transportation, and savings. If we earn $x$ dollars per month and want to allocate $30\%$ to housing, we can calculate the amount using the ratio $\frac{30}{100}=\frac{y}{x}$, where $y$ represents the housing budget.
3. Maps and Scales: Maps often use scales to represent real-world distances accurately. The scale of a map is a ratio that compares the distance on the map to the actual distance on the ground. For example, if $1$ inch on a map represents $10$ miles, we can use the proportion $\frac{1}{10}=\frac{y}{m}$ to determine that $y$ inches on the map represent $m$ miles in reality.
4. Proportional Relationships: Many everyday situations involve proportional relationships. For instance, the cost of goods in a grocery store often depends on their weight. If bananas cost $2$ dollars per pound, we can use the ratio $\frac{2}{1}$ to find that $5$ pounds of bananas would cost $10$ dollars.
5. Scaling and Enlargement: Ratios and proportions are used when scaling or enlarging objects. For example, architects use proportions to create scaled-down models of buildings. If a building is $100$ feet tall and the model is $2$ feet tall, the ratio of their heights is $\frac{2}{100}=\frac{y}{x}$, where $y$ represents the desired height of another object with unknown $x$.
These are just a few examples of how ratios and proportions are used in everyday life. They provide a way to compare quantities, solve problems, and make informed decisions based on relative relationships between values.