A Six Sigma analyst in Lakerside United Bank suspected that errors in counting and manually strapping cash into bundles were related to the number of weeks that employees had been employed on that job. The data available in the worksheet below were gathered from the process.
1. Draw and label a scatter diagram depicting the data. What, if anything, do you learn from the scatter diagram?
2. Does the scatter diagram confirm or refute your suspicions about errors being related to the number of weeks employed? Explain.
3. What might explain the difference in error rates before and after week 26? How would you go about trying to better understand the cause of this difference? What additional tools would you use to further understand the problem and identify solutions? Explain why you select those tools.
