Suppose a pet supplies company uses three manufacturing centers for the production of its cat toys. The defect classification for item production contains three levels: no defects, minimal defects but still acceptable for use, and significant defects where the item does not meet quality standards.
Connor, a quality assurance specialist at the pet supplies company, plans to run a chi-square test of homogeneity to determine if the proportion of cat toy items in each defect category is the same across the three manufacturing centers. He sets the significance level for the test at =0.05.
He randomly selects 388 items from Center A, 406 items from Center B, 274 items from Center C, and records the defect classification of each item.
The sample results are summarized in the contingency table.