Two machines produce steel rods whose lengths (in cm) for one sample run are:
Machine A: 20.1, 20.0, 19.9, 20.2, 20.0, 20.4
Machine B: 20.0, 19.7, 20.3, 19.9, 20.1, 19.8
(i) Determine the range for each machine.
(ii) Determine the standard deviation for each machine, correct to three decimal places.
(iii) If the specification requires lengths to stay as close as possible to 20 cm (tolerance ±0.3 cm), which machine would you recommend and why?