Determine the means for the following sets of results: (a) the times taken for 10 oscillations of a simple pendulum: 51, 49, 50, 49, 52, 50, 49, 53, 49, 52 s; (b) the diameter of a wire when measured at a number of points using a micrometre screw gauge: 2.11, 2.05, 2.15, 2.12, 2.16, 2.14, 2.16, 2.17, 2.13, 2.15 mm; (c) the volume of water passing through a tube per 100 s time interval when measured at a number of times: 52, 49, 54, 48, 49, 49, 53, 48, 50, 53 cm3 .