I get pass all the tests except for Test 3, where I get 306.9401397549153. My solution is based on a closed form solution, so I don't see how it's wrong. It is also equivalent to the results from Mathematica.
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: United States.
You can also select a web site from the following list
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.