Final answer:
The Nile River is approximately 6611 km long.
Step-by-step explanation:
To find the length of the Nile River, we can use the given information that it is 209% the length of the Yukon River. First, we need to calculate 209% of 3168 km. To do this, we multiply 3168 km by 209% (or 2.09).
So, 3168 km * 2.09 = 6610.72 km.
Rounded to the nearest kilometer, the length of the Nile River is approximately 6611 km.