When we originally posted the practice final, we did not explicitly plan to post a key to solutions. Since then, a number of students asked whether sample solutions could be posted. Although we might still attempt to do so (our primary priority is vetting the actual exam, and providing you feedback on your assignments pending final grading) we cannot promise that a key will be given to you, especially soon enough for it to be helpful. We hope you still find the practice questions useful in testing your familiarity with certain topics that might appear in the final.
That being said, prior to the midterm we witnessed a very nice community effort on Piazza of coming up with answers by sharing individual opinions. If some of you are inclined to start a similar thread, this would be a very nice alternative! (and maybe it would be easier for instructors to contribute short answers/explanations in such a discussion).
