Exercises

The following exercises involve examples and problems from Devore and Peck [11]. The data sets are in files in the folder Data on the XLISP-STAT distribution disk and can be read in using the   Load item in the File menu or using the load function (see Section 5.4 below). To use the Load item on the File menu select this item from the menu. This will bring up an Open File dialog window. Use this dialog to open the Data folder on the distribution disk. Now select one of the .lsp files ( car-prices.lsp for the first exercise) and press the Open button. The file will be loaded and some variables will be defined for you. Loading file car-prices.lsp will define the single variable car-prices. Loading file heating.lsp will define two variables, gas-heat and electric-heat.

1. Devore and Peck [11, page 18, Example 2,] give advertised prices for a sample of 50 used Japanese subcompact cars. Obtain some plots and summary statistics for this data. Experiment with some transformations of the data as well. The data set is called car-prices in the file car-prices.lsp. The prices are given in units of $1000; thus the price 2.39 represents $2390. The data have been sorted by their leading digit.

2. In Exercise 2.40 Devore and Peck [11] give heating costs for a sample of apartments heated by gas and a sample of apartments heated by electricity. Obtain plots and summary statistics for these samples separately and look at a parallel box plot for the two samples. These data sets are called gas-heat and electric-heat in the file heating.lsp.