
472 A First Course in Quality Engineering
The Minitab program calculates the percentage frequency of occurrence
for each of the causes and then rank orders them based on the percentage fre-
quency� It also computes the cumulative percentage frequency of the causes,
and graphs the cumulative frequency� The percentage frequency and cumu-
lative percentage frequencies are shown in the table below the graphs� The
cumulative frequency table and graph help in reading off the graph, the most
important causes� For example, in the above case study, “curing humidity”
and “curing temperature” can be read from the graph as being the two domi-
nant causes, ...