Workers in three different but comparable companies were asked to rate the use of quality-control techniques in their firms on a 50-point scale. A score of 50 represents nearly perfect implementation of quality control techniques and 0 represents no implementation. Workers are divided into three independent groups. One group worked in a company that had required all its workers to attend a 3-day seminar on quality control 1 year ago. A second group worked in a company in which each worker was part of a quality circle group that had been meeting at least once a month for a year. The third group of workers was employed by a company in which management had been actively involved in the quality-control process for more than a year.

Use a = .10 to determine whether there is a significant difference between the three groups, as measured by theratings.

Attended 3-Day Qity Management Circles 27 38 25 40 31 19 35 Involved 16 21 18 28 29 20 31 Seminar 17 10 15