Final answer:
The speed walker will walk 6 3/4 miles in 3/4 hour when walking 1.5 times faster and 2 1/4 miles in 3/4 hour when walking twice slower.
Step-by-step explanation:
To determine how far the speed walker will walk in 3/4 hour when walking 1.5 times faster, we can multiply the distance covered in 3/4 hour by 1.5. 4 1/2 miles multiplied by 1.5 is 6 3/4 miles. Therefore, the speed walker will walk 6 3/4 miles in 3/4 hour when walking 1.5 times faster.
To determine how far the speed walker will walk in 3/4 hour when walking twice slower, we can multiply the distance covered in 3/4 hour by 1/2. 4 1/2 miles multiplied by 1/2 is 2 1/4 miles. Therefore, the speed walker will walk 2 1/4 miles in 3/4 hour when walking twice slower.