Use the ratio-proportion method to solve for the unknown. How many kilograms are in 6.5 pounds? Round the answer to the nearest hundredth. Use the following equation, where the known value is 1 kilogram = 2.2 pounds: x kg6.5 lb=1 kg2.2 lb kg
The Correct Answer and Explanation is:
To solve for how many kilograms are in 6.5 pounds using the ratio-proportion method, we set up a proportion based on the known conversion:
1 kilogram = 2.2 pounds
We want to find how many kilograms, denoted by x, are equivalent to 6.5 pounds. So we set up the proportion:
x kg / 6.5 lb = 1 kg / 2.2 lb
To solve this proportion, we cross-multiply:
x × 2.2 = 1 × 6.5
This gives:
2.2x = 6.5
Now, solve for x by dividing both sides of the equation by 2.2:
x = 6.5 / 2.2
x ≈ 2.954545
Rounded to the nearest hundredth:
x ≈ 2.95
Final Answer:
2.95 kilograms
Explanation:
The ratio-proportion method is useful when converting units based on a fixed relationship. In this case, the fixed relationship is that 1 kilogram is equal to 2.2 pounds. This means that the ratio 1 kg / 2.2 lb must remain constant, no matter the values used. By setting the unknown number of kilograms over 6.5 pounds equal to the known ratio, we can cross-multiply and solve for the unknown.
Cross-multiplying ensures both sides of the proportion remain equal. Once we isolate x (kilograms), we divide and then round the result to the nearest hundredth, since the question asks for this level of precision.
This method is widely used in science, health, and cooking for converting measurements between different units, such as pounds to kilograms, inches to centimeters, or Fahrenheit to Celsius.
