Motion of a simple pendulum

I created a simple pendulum by hanging a weight from a string. I varied the length of the string and measured the time for 10 oscillations of the weight.

                                                                      2
length(cm)   time for 10 swings        Period                 (Period)
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   7.3       5.52,  5.40,  5.67



  15.5       7.97,  8.00,  7.92



  29.8      11.38, 11.30, 11.21



  59.0      15.35, 15.55, 15.70



  97.0      20.12, 20.03, 19.88



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1. Fill in the "period" and "period-squared" columns of the table above, computing and writing down the value for each of the measurements. Do not take averages.
2. Create one graph for this data. Make a graph of the period squared versus the length of the string.
3. Determine the slope of line connecting these measurements and the uncertainty in the slope.
4. Use the slope (and uncertainty) to compute a value for the local acceleration due to the gravity (and its uncertainty). Does your value agree with the standard one?

5. Use your graph to find the length of a pendulum which would have a period of exactly one second. Does that length have any significance?