Description
Assignment #8
Part A. In reviewing the data in the Performance Lawn Equipment database (worksheet Defects after Delivery), we noticed that in 2014 and 2015 PLE experienced some quality problems due to an increasing number of defects in materials received from suppliers. But after the quality improvement initiative conducted in August 2015, defects received from suppliers have decreased. Plot the data using a scatter chart and then use a linear function to model the relationships between month and the rate of defects before and after August 2015 (two charts). I have already separated the data for you. Interpret the results.
Part B. PLEs human resource director has a concern about the high rate of turnover in its field service staff. We want to identify the characteristics of individuals that lead to greater retention. Use the data in the worksheet Employee Retention and conduct a statistical study to determine the effect that years of education, colege grade point average, age, gender, College Grad, and local have on retention (yearsPLE). A sample of 40 field service engineers was selected to determine the influence of these variables on how long each individual stayed with the company. Evaluate the full regression model, then use systematic model building approach to identify the best model.
(Simply run the regression models, no need to check the regression assumptions and multicollinearity for this assignment.)
Part C. As part of its efforts to remain competitive, PLE tries to keep up with the latest in production technology. The lawn mower division spends a great deal of effort in testing new technology. One example is the production of a new design for lawn mower engines. To determine the time required to produce these engines, PLE produced 50 units on its production line. Test results are recorded on the worksheet Engines in the database. Create a scatter chart then use Excel trendline tool to find the function that is best fit to the data.