Answer:
4 miles
Explanation:
We can let "w" stand for the width of the park. Its area is the product of its length (3/8·w) and its width:
6 mi² = (3/8·w)w = 3/8·w²
16 mi² = w² . . . . . multiply by 8/3
√(16 mi²) = w = 4 mi
The width of the park is 4 miles.