Final answer:
To find out how many pounds there are in 7 kilograms, multiply the number of kilograms (7) by the conversion factor (2.2 pounds per kilogram), resulting in 15.4 pounds.
Step-by-step explanation:
The question asks how many pounds are in 7 kilograms. To convert kilograms to pounds, the general equation is: kilograms multiplied by the conversion factor (2.2 pounds per 1 kilogram). Using this information, the conversion is straightforward:
7 kg × 2.2 pounds/kg = 15.4 pounds
In terms of significant figures, since 2.2 has two significant figures, our final answer should also be expressed with two significant figures. Here, we do not need to worry about exact numbers, as the number of kilograms is given and is not an exact number by definition. Therefore, the answer does not change, and it remains as 15.4 pounds.
As a practical matter, using kilograms as a unit of measurement often simplifies the numbers we work with because it is a base unit in the metric system. However, when converting to pounds, which is a customary unit, we use the conversion factor as explained above for accuracy and consistency.