The lab report to be submitted by the following meeting (i.e. the next lab or recitation, which ever comes first) consists of writing some well-formed responses to the following questions. There is no strict format for this, but treat each question as a point of departure for an intelligent discussion. You don't need to write a book for each one, but one line answers would be considered too brief.
Discuss the limitations of these methods for calculating $\pi$. Which method was the best? The worst? Are there improvements to be made?
Determine the uncertainty of your density measurement. This will involve some algebraic calculation. You can find some pointers here: Info about error analysis. Next, find an online database that you can use to lookup the density of various woods. Try to match your piece of wood with a known tree. Discuss whether you can be certain of your identification.
Based only on your experimental data, can you say how the time for one swing relates to the length of the pendulum? Is there a clear functional dependence?
Is there a correlation between the circumference of someone's head and the time between heartbeats? Would you expect there to be one?