Special causes. Is each of the following examples of a special cause most likely to first result in (i) one-point-out on the s or R chart, (ii) one-point-out on the chart, or (iii) a run on the chart? In each case, briefly explain your reasoning.
(a) The sharpness of a power saw blade deteriorates as more items are cut.
(b) Buildup of dirt reduces the precision with which parts are placed for machining.
(c) A new customer service representative for a Spanish-language help line is not a native speaker and has difficulty understanding customers.
(d) A nurse responsible for filling out insurance claim forms grows less attentive as her shift continues.