Please help me find percent error and questions 1 & 2.

Table 1: Rotational Data Time per 15 Radius revolutions Period (s) Expected Value Percent Error (%) 0.25 4.84 0.40 4.66 0.15 5.12 0.325 0.539 0.184 0.501 0.635 0.389 Post-Lab Questions Compare your measured data to your predicted values with a percent error calculation. Explain any differences with an error analysis. 1. 2. How did the period of rotation vary as you changed the radius