This is by far the worst online class I have ever taken. My answers were never able to submit, the issues never were resolved, I'm two weeks behind, and now on top of everything they won't refund me. No call center, the chat support bots never got back to me with a human and I am ultimately very frustrated and dissatisfied. If one of coursera's classes is somehow your last class until you graduate like me, I highly recommend not wasting an ounce of your money or time on this poorly ran online pile of rubbish.