Final answer:
The length of a marathon is 42.188 km, and converting 26 miles to kilometers using the conversion factor of 1 mile = 1.61 km results in approximately 41.86 km.
Step-by-step explanation:
The length of a marathon in kilometers is typically 42.188 km. To convert miles to kilometers, you use the conversion factor that 1 mile is approximately equal to 1.61 kilometers. Since you're aiming to complete a 26-mile race, the calculation would look like this: 26 miles × 1.61 km/mile = 41.86 km. So, for your marathon goal, you would be running roughly 41.86 kilometers.