Brynne Packaging is a large packaging company, offering its customers the highest standards in innovative packaging solutions and reliable service. About 25% of the employees at Brynne Packaging are machine operators. The human resources department has suggested that the company consider using the Wesman Personnel Classification Test (WPCT), a measure of reasoning ability, to screen applicants for the machine operator job. In order to assess the WPCT as a predictor of future job performance, 25 recent applicants were tested using the WPCT; all were hired, regardless of their WPCT score. At a later time, supervisors were asked to rate the quality of the job performance of these 25 employees, using a 1-to-10 rating scale (where 1 = very low and 10 = very high). Factors considered in the ratings included the employee's output, defect rate, ability to implement continuous quality procedures, and contributions to team problem-solving efforts. The file BrynnePackaging contains the WPCT scores (WPCT) and job performance ratings (Ratings) for the 25 employees.

1. Assess the significance and importance of WPCT score as a predictor of job performance. Defend your answer.

2. Predict the mean job performance rating for all employees with a WPCT score of 6. Give a point prediction as well as a 95% confidence interval. Do you have any concerns using

the regression model for predicting mean job performance rating given the WPCT score of 6?

3. Evaluate whether the assumptions of regression have been seriously violated.