Relative Error!? If the relative error for the radius of a circle is 5%, what is the relative error for the circumference? I know that relative error is the ratio of the absolute error in a measurement to the size of the measurement, but I honestly have no idea how to complete the problem. These are one of the pre-lab problems, where we're supposed to try and figure it out before we're taught it, but I'm stumped on this one. PLEASE HELP!!