4. The equation for the circumference of a circle is: C = 2r, where "r" is the radius of the circle. The table below contains data used to experimentally determine the value of . Calculate the average of each column, then using the equation for circumference, calculate the value of . Trial 1 2 3 4 5 Average C (cm) 26.91 26.89 26.67 26.93 27.07 r (cm) 4.30 4.29 4.28 4.29 4.33 5. Using the known value of , 3.14159, calculate the percent error of our answer from problem 4. % Error =