The output voltage from a precision 12 V power supply, monitored at intervals over a period of time, produced the following readings: V_{1} = 12.001V V_{2} = 11.999V , V_{3} = 11.998V V_{4} = 12.003V V_{5} = 12.002V V_{6} = 11.997V V_{7} = 12.002V V = 12.003 V, V_{9} = 11.998V and V_{10} = 11.997V Calculate the average voltage level, the mean deviation, the standard deviation, and the probable error in the measured voltage at any time,