Operations and production managers often use the normal distribution as a probability model to forecast demand in order to determine inventory levels, manage the supply chain, control production and service processes, and perform quality assurance checks on products and services. The information gained from such statistical analyses help managers optimize resource allocation and reduce process time, which in turn often improves profit margins and customer satisfaction.
Based on your understanding of the characteristics of the normal distribution, examine the chart below. Process A standard deviation is .9, Process B standard deviation is 1.4, and the mean of both processes is 12. Contribute to our discussion by posting a response to ONE of the questions below.
Do either of the processes fit a normal distribution? Why or why not?
Which of the processes shows more variation? What does this mean practically?
If the product specification quality limits were 12 +/- 3, which of the processes more consistently meets specification? Explain why.
If the product specification quality limits were changed to 12 +/- 6, is quality loosening or tightening? Which process would benefit the most from this change?
Are there processes at your place of employ that you believe follow a normal distribution? If so, describe one. Why do you believe it is normal?
2. Hang Up and Drive : Check out this snippet from Family Circle magazine (January, 2009, Liz Plosser):
Motorists who talk on a cell phone while driving are 9% slower to hit the brakes, 19% slower to resume normal speed after braking and four times more likely to crash.
Interesting, eh? Need more information? Sorry, that’s all the information this article provided. So, what can we conclude? How reliable are these results? Can you believe what the author tells you? Why or why not?
Pretend you’re a manager for one of the major cell phone service providers in the U.S. You’ve been asked by a major news magazine to speak to these “accusations.” What would you say? Use your knowledge of “statistics for managers” to level some well-founded criticisms of the conclusions above.
Careful! We cannot use personal opinions to battle statistics like these! Instead, you must explain why the numbers reported in Family Circle may, or may not, accurately represent the population of U.S. drivers. There are 100 possible answers to this conference topic.
You need only provide a single idea, to get the conversation rolling. Leave some material for others to contribute. Be sure that your contribution explicitly references what we’ve read and practiced in the class so far. It is your classmates’ job to support or refute what you’ve said.
3. Confidence Intervals at the Workplace
Web site:
https://www.mathsisfun.com/data/confidence-interval.html
https://mathbitsnotebook.com/Algebra2/Statistics/STmarginError.html
Case scenario.
At the workplace, you are the research team leader.
The Boss wants your team to collect data to establish a confidence interval for a situation at work.
In 6-sentences or more, explain how confidence interval procedure can be applied at the workplace for the situation.