Answers for checking:

1. avgSeaIceExtentAnnual should be a vector with 35 elements. The first and last are, respectively, 12.3537 and 10.9340.
2. The answer should be a vector with 24 elements. The first and last are, respectively, 13.7589 and 12.8673.
3. 11.5863
4. Should have 35 answers. The first five are: 14, 14, 14, 15, 15. The last the are 13 and followed by nine 12's. 
5. 14
6. 10
7. 2012        2007        2011        2010        2006        2005        2013        2009        2008       2004
8. The answer can be -1.8078 or 1.8078. If you answer is not one of these two numbers (or specifically -0.0104), then it is not correct.
9. The 5th half-month or first half of March