How is Uncertainty Propagated in Pendulum Period Measurements?

[RaamGeneral]

Hello.
I have measured the period of the pendulum
T=2.18 +/- 0.02

which is consistent with the true period 2.19865... so I expect myself to find a consistent value of g if I apply the formula propagating the error in the right way.

I get
g=9.96 +/- 0.2Why?

 

[bhillyard]

Assuming you are referring to a simple pendulum what is it's length, and the error in that measurement? The final calculated value for g will involve both errors .

 

[RaamGeneral]

Thanks for your reply. Length is 1.20 meter without error. I'm training myself with a simulation on computer. The problem here is calculation, I discovered that usually to find g, we find the slope of the line L = g/4pi^2 * T^2
I also noticed that if i take T = 2.20 and T = 2.16, and I calculate g, the real value is between them.