River-stage observers recorded the water-level deviations (in cm, positive for above and negative for below the reference line) at eight different times of a day:
12.4,−8.3,5.0,−11.6,9.2,−2.7,0.0,14.8
(i) Arrange the readings in ascending order and find the range.
(ii) A systematic error later required that each reading be reduced by 1.2cm. Without recalculating every individual value, determine the adjusted range.
(iii) It was later discovered that the reading −11.6cm had been mis-copied and should actually be −6.6cm. Keeping the other corrected data the same as in part (ii), compute the final range.