Stat 408 Assignment 1.2

Due January 23, 2013
Show R code and output for each exercise. Use any font for comments and explanations, but use courier (or other fixed-width) font for computer input and output. Insert plots near your code and discussion, not all at the end of the assignment.
  1. A dataset at the JSE site is in .xls format. Download it, open it in a spreadsheet, and save it as comma separated values and read it into R. Descriptive info is here.
    1. Provide a plot which shows how the distribution of Price varies with Type.
    2. To what degree is Price affected by Mileage? Provide a plot and discuss.
    3. Compare proportions of cars with Leather among the 5 Types with a plot.
  2. Superbowl XLVI is scheduled to be played February 5 in Indianapolis. I've pulled together some data about previous Superbowls so that you can impress friends with your recall. However, the data file needs some work before you can read it into R.
    1. Examine this file and figure out what problems prevent R from reading it in directly. Explain what changes you make so that it is readable. (Reminder: do not edit it in Word. Use a text editor like Wordpad or Eclipse.)
    2. Read the data into an R dataframe.
    3. Create new variables for the total score and the winning margin.
    4. Print out a summary of the data frame.
    5. Is there a trend to the total score over time?
    6. Point spread (winning margin) is of interest to odds makers. Plot and summarize its distribution.
    7. Is there a trend to the point spread over time?