Significant figures in a results table

[Alexander350]

Homework Statement

Basically there is a results table for the time taken for 20 oscillations. Three examples are 9.90, 11.16 and 12.68. I need to work out the time period to the correct number of significant figures.

Homework Equations

The Attempt at a Solution

I divide by 20 to get the time period but should it be to two, three or four significant figures? Because the number of oscillations is only to 2 s.f. I'm thinking it should be two but since that is part of the method and not a measurement per se, should I use the same number of significant figures as the time?

Apparently the answer is 3 significant figures for all of them.

 

[TheReal NdGT]

3

 

[TheReal NdGT]

3

 

[haruspex]

Because the number of oscillations is only to 2 s.f

So you are thinking the actual number of oscillations may have been anything from 19.5 to 20.5?