Im doing Physics Lab 2: Balancing Centripetal Force. On my table 1 data sheet, for 0.25m I got 6.42 Seconds, 0.40m - 7.78S, and 0.15m - 5.09S. I dont know how to get the "Period(s)" or the "expected value" and the "percent error". Please tell explain how to get those 3 and how to plug in my numbers please.