Tests of product quality using human inspectors can lead to serious inspection error problems (Journal of Quality Technology). To evaluate the performance of inspectors in a new company, a quality manager had a sample of 12 novice inspectors evaluate 200 finished products. The same 200 items were evaluated by 12 experienced inspectors. The quality of each item-whether defective or non defective-was known to the manager. The table lists the number of inspection errors (classifying a defective item as non defective or vice versa) made by each inspector.

a. Prior to conducting this experiment, the manager believed the variance in inspection errors was lower for experienced inspectors than for novice inspectors. Do the sample data support her belief? Test using α = .05.
b. What is the appropriate p-value of the test you conducted in part a?

Transcribed Image Text:

Novice Inspectors Experienced Inspectors 30 35 26 40 31 5 25 19 36 20 45 31 28 17 19 18 33 29 21 48 24 10 20 21