CS 147 Homework Assignment 1

This homework assignment is due at 12 AM on Thursday, February 13, 2003 (i.e., the Wednesday/Thursday boundary). Please give your solutions to me or place them in the box outside my door.

Most of the problems in this assignment are taken from the textbook. I expect that it will take you about 2 hours to complete the assignment.

If you use a Microsoft product to do your graphing, be sure to turn off all colors (so you can print in black and white) and the stupid gray background.

Problems from the textbook: 12.7 through 12.15.

Additional problems:

12.16
What is the skewness (see box 12.1 on page 197) of the data from problem 12.15? What is the kurtosis? The kurtosis is calculated by using an exponent of 4 instead of 3 in the skewness equation, and then subtracting 3 from the result, as follows:
kurtosis = [ 1/(n*s^4) * sum[(xi-xbar)^4] ] - 3
A skewness significantly far from zero indicates a skewed distribution. A kurtosis with an absolute value greater than about 0.5 indicates a distribution narrower (negative) or wider (positive) than a normal distribution.
12.17
Do the skewness and kurtosis you calculated in 12.16 support the conclusions you reached in 12.15?
12.18
(Extra credit.) Plot a kernel density estimate of the data from problem 12.15, using either a Gaussian or a triangular kernel. If you used an existing software to create the plot, identify the package (I'm looking for good packages).

Notes:

To save you pointless typing, here are links to the data given in some of the problems:

  • 12.10
  • 12.11
  • 12.15

    • For problem 12.7, you may find the tables in Appendix A useful, or you might choose to use a program with statistical functions, such as Excel or Matlab. In problem 12.7b, interpret "less than" as "less than or equal to".

    © 2003, Geoff Kuenning

    This page is maintained by Geoff Kuenning.