| 23
January |
- Create histograms and EDF plots (see class notes)
of the data in exercises 3.1, 3.2, 3.7, and 3.8. Do at least
one set by hand and do at least one set using software. (Links
to web applets for histograms are available in the class notes
section). [60 min]
- Construct stem-and-leaf plots for the following
batches. Make them effective: putting all the leaves on
a single stem does not count! [45 min]
{299937, 299964, 299931, 299905, 299971, 299969, 300001, 299950,
299948, 299955}
{3.3340E-6, 3.3337E-6, 3.3341E-6, 3.3344E-6, 3.3337E-6, 3.3337E-6,
3.3333E-6, 3.3339E-6, 3.3339E-6, 3.3338E-6}
{0.01, 0.1, 1, 10, 100, 1000, 10000} [powers of 10]
{1, 2, 4, 9, 16, 25, 36, ..., 361} [squares]
{1, 1/2, 1/3, 1/4, 1/5, ..., 1/17} [reciprocals]
{-8, -6, -4, -2, -0.5, 0.5, 1, 3, 5, 7, 9} [negative and positive
values in the same batch]
- Create a program or spreadsheet that displays EDF
plots using (a) ranks and (b) percentiles. The input to the
program or spreadsheet should be an ordered list of data.
Apply your work to the data in assignment 1. [60 min]
- Make sure you have a working spreadsheet for
computing descriptive statistics. Compare your efforts from
the 16 January homework assignment with the sample
solution. Using the sample solution if necessary, complete
16 January assignment 5. Here it is again, for easy reference:
- Create a spreadsheet, computer program, or
calculator program to generate summary statistics for a batch of
data. Do not use any built-in functions or macros
(except for sorting and ranking, where appropriate). Instead,
compute the statistics directly from the formulas (as provided in
the textbook or obtained elsewhere). The statistics should
include:
 | Mean, Variance, Standard deviation (sd),
Coefficient of variation (cv) |
| Maximum, Minimum, Median, Range [requires order
statistics or sorting] |
| Skewness, Kurtosis |
| Geometric mean, Geometric sd [requires
logarithms] |
| Median absolute deviation (mad) |
| Trimmed mean, for arbitrary trimming between 0%
and 50%. |
Complete any parts of the 16 January homework
assignment you were unable to do.
Total estimated time: 3:15+ hours
Comments
 | Assignment #1 lets you practice with familiar
data. Do more or fewer of these exercises depending on how
comfortable you are. Your goal is to be able to make a
histogram and EDF plot of a batch quickly and unhesitatingly. |
| Assignment #2 uses some tricky batches.
Remember the point of the stem-and-leaf diagram is to show the
shape of the data. Look around the web (follow links from
these pages) for examples to help you. If you get stuck, type
up your attempt in a plain text e-mail and forward it to me for
advice. |
| Assignment #3 is important: it will be followed up
next week with a probability plot exercise. Probability plots
are essential tools and constructing an EDF plot is a key
intermediate step in making a probability plot. |
| The remaining assignments give you a chance to
catch up: last week's assignment was long. |
| The reading for this week is the same as for last
week. |
| As always, study this week's class notes.
Make sure you know the terminology presented last week and this
week. |
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