There is an error in Assignment 9, problem 4, parts (e) and (g) – several students have reported entering the correct answer (which I have confirmed), but WeBWorK rejects it.
Even more strange, part f is graded correctly, even though it includes the answer that was rejected in part e.
I am following up with our WeBWorK administrator on this problem. For now, please complete all parts of the problem except (e) and (g).
Sincere apologies for any mental or emotional harm this may have caused.