The first due date for a Part 5 assignment is tonight. And you have today through Wednesday to complete Test #2. So this week we're wrapping up the old and starting the new. Part 5 is the only piece of the course that has a test devoted entirely to it. (Test #3 will be on Part 5 and nothing else.) And do remember that Part 5 draws heavily on Part 4. Very frequently a student will say "I don't understand probability," when what they really mean is that they don't understand the techniques in Part 4 that are being applied to probability situations.
As always, stay in touch with me or Jenn regarding any issues you run into in this class.