Question: Rolled Paper. Shervheim and Snider did a project with a company that cuts rolled paper into sheets. The students periodically sampled n = 5 consecutive sheets as they were cut and recorded their actual lengths, y. Data from 20 subgroups are summarized in Table. (Measurements corresponding to the values in the table were in 64ths of an inch above nominal, i.e., x = y - nominal.)
(a) Make a retrospective s chart.
(b) Make a retrospective x chart.
(c) What do these charts indicate (in retrospect) about the stability of the cutting process?
(d) Give an estimate of the process standard deviation based on s.
(e) If one judges the process to be stable and sheet length to be normally distributed, estimate the fraction of sheets below nominal in length
