Answer
B>E>D>A>C
Work Step by Step
We are looking at 2 factors to determine the quality of timekeeping for the 5 clocks:
1. the time difference between consequent days for the same clock. Technically speaking, there should be 0 difference between the time recorded on consecutive days, but because of the non-uniform motion of the hands, it is not the same.
2. Noon means sharp 12:00:00. however, the table above shows a range of time recorded for a clock at noon. hence, lower the standard deviation of the time range about noon, the better a timekeeper a clock is.
B has the lowest standard deviation. the timing recorded everyday is almost the same (differing by only 7 seconds) and accurate to noon.
Next is E, which is close to noon too, but varies by 1-4 mins in the increasing direction
D varies by 4 minutes in the increasing and 3 in the decreasing direction. Hence, its range is 7 mins about noon.
A varies by 38 mins in the increasing direction and hence is considerably inaccurate than the others.
C varies by 3 hrs and is hence the worst timekeeper.
