*Before I start, I just want to say that this is only my second day in IB Physics. I had never taken Physics at in in high school prior to IB Physics, so I really had to read up and pretty much self-teach myself a bit of it over the summer. Of course, even now I still have absolutely no idea what I'm reading (but neither does anyone else in my class). The answers and explanations to these problems are only based on my meager understanding of Physics.* 1. The problem statement, all variables and given/known data You measure the oscillations of a pendulum four times, and find that it makes 15 complete swings in times of: 8.13 s, 8.22 s, 8.19 s, and 8.15 s. You calculate a standard deviation (read from your calculator) of 0.0403112887416037 s. The correct way to report the answer (with the proper number of significant figures!) is to say that the period is: ? seconds With an uncertainty of: ? seconds *There is little tolerance for error in this specific question* 2. Relevant equations -I entered the variables in my calculator just to see what the average was. I got an average of 8.17 seconds using the sig-fig calculator and the standard deviation was the same. (There really aren't any relevant "equations" in this problem) 3. The attempt at a solution -Based on what I learned, you can only express uncertainties in one sig-fig, and that it must match the level of precision. So, based on that I wrote down: 8.17 ± .04 seconds. But, apparently this is wrong. Why? Any help is gratefully appreciated.