1.10 Kister (Trans IChemE, 2003) studied malfunctioning of distillation towers. Table below lists the number of cases stratified by different causes.

The data are also stratified by the year of failure

(“Prior to 1991” or “1992 and Later”).

a Construct an appropriate plot to describe this data.
b Compare “Prior to 1991” failures with “1992 and Later” failures.

Transcribed Image Text:

Tower Malfunctioning Total Prior to 1992 and Cause cases 1991 Later Coking 26 4 22 Scale, corrosion products 22 11 11 Precipitation, salting out 17 4 13 Solids in feed 10 6 Polymer 9 3 45