A horizontal angle was measured by repetition six times with an engineer’s transit. Prior to measurement, the horizontal scale was at 0 and the reading on the scale was 84 deg 38’ after the angle was measured once. If the final reading was 147 deg 42 min, the average value of the angle measured is ___

A horizontal angle was measured by repetition six times with an engineer’s transit. Prior to measurement, the horizontal scale was at 0 and the reading on the scale was 84 deg 38’ after the angle was measured once. If the final reading was 147 deg 42 min, the average value of the angle measured is ___