Question

The quality manager believes there may be a relationship between the experience level of an inspector and whether a product passes or fails inspection. Inspection records were reviewed for 630 units of a particular product, and the number of units which passed and failed inspection was determined based on three inspector experience levels. The results are shown in the following table.

Decision Experience Level
Low
(< 2 years) Medium
(2-8 years) High
(> 8 years)
Pass 150 285 103
Fail 15 44 23

a. Select the competing hypotheses to determine whether the inspector pass/fail decision depends on experience level.