Answer: the speed of the boat is approximately 9.43 miles per hour.
Step-by-step explanation: To find boat speed, add vectors. Boat goes east at 8 mph, with 5 mph north wind. Boat velocity is a vector eastward and current velocity is a vector northward. To combine velocities, use vector addition. Use Pythagorean theorem to find resultant velocity: resultant speed = √89 ≈ 9.43 mph.