Final answer:
Proportions involve setting two ratios equal and cross-multiplying to solve for the unknown. Examples include unit conversion and scaling measurements for models. The process involves simple multiplication and division steps to find the desired value.
Step-by-step explanation:
To solve proportions, we set two ratios equal to one another and then cross multiply to find the unknown variable. For example:
- For the proportion 5/1 = x/2.75 (in centimeters), cross multiplying gives us 5 × 2.75 = 1 × x, which simplifies to x = 13.75.
- When converting units, such as finding how many milliliters are in 2.5 liters, we know that 1 liter is equivalent to 1000 milliliters. Hence, we set up the proportion 1 liter/1000 mL = 2.5 liters/x mL and solve for x to find that x = 2500 milliliters.
- In the case of scaling models, if the scale is 1 cm for every 0.5 m and the model is 150 cm tall, we set the proportion 1 cm/0.5 m = 150 cm/x m and find that x = 75 m in the actual size.