Answer: His percent error = 5.38 %
He overestimated the gradient.
Step-by-step explanation:
Formula : [tex]Percent\ error =\dfrac{|Estimated\ value- Actual\ value|}{Actual\ value}\times100[/tex]
Given, Estimated gradient of trail = 213.6 ft/mile
Actual gradient of trail = 202.7 ft/mile
Since, 213.6 > 202.7 , that means he overestimated the gradient.
Percent error: [tex]\dfrac{|213.6-202.7|}{202.7}\times100[/tex]
[tex]=\dfrac{10.9}{202.7}\times100\\\\\approx5.38\%[/tex]
Hence, percent error = 5.38 %