Chapter 11: Time Series.
- Use the
Dow.xls
workbook, plot the time series
and answer the following question: "How variable are
the average Dow values from one month to another?"
- Why in the process of your analysis might it
be useful to transform the values to stabilize the variance? What do you do?
- What are "lagged values" and what significance do they
have in our experiment? What is the autocorrelation function and
what's it used for?
- Describe some typical ACF patterns. Does any one of
them applies to the Dow example?
- What are moving averages? What is simple exponential smoothing?
In the Dow example (the section on forecasting to guide decisions) how do
you calculate the buy or sell signal for each month? Is exponential smoothing
well suited to predicting short-term market activity? Why or why not?
- Describe the basic idea behind two-parameter exponential smoothing.
- The example on page 446 starts with the question: "Is beer production
seasonal?" What does the chapter do to answer this question and what is the answer?
Chapter 12: Quality Control.
- What is the purpose of a control chart?
- Where and how did statistical process control originate?
- (Fill in the blank) From the book: "SPC is a
methodology for distinguishing whether variation is _________
or __________." Explain the relative significance (and remedies).
- What is the difference between variable and attribute
charts and when/why are they used?
- Briefly (and completely) summarize the example presented
in the book for calculating control limits when the standard deviation
is known.
- What case-study does the workbook
Coats.xls
refer to? What is the conclusion? How is it reached? Is it justified?
- How is the C-chart used in the book to help with SPC and what
is the monitored process?
- What are the relative merits of P-charts?
- How do you create control charts for processes
that cannot be neatly divided into subgroups?
- What is a Pareto chart and when is it useful?