Stat 408 Assignment 1-1

Due: January 16, 2013
Write up your solutions in a word processor, or as an html document, or with LaTeX.
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. Create and print a sequence
    1. of integers from 128 to 143. Use the length function to count how many there are.
    2. of integers from 100 to 80. Again provide the vector length.
    3. of nine equally spaced real numbers from 0 to π. Note pi is predefined in R. Which of these have sin zero? Which have cos of 0?
  2. Read in the data set of kids feet sizes
    www.amstat.org/publications/jse/datasets/kidsfeet.dat.txt
    and look at the page which describes the variables.
    www.amstat.org/publications/jse/datasets/kidsfeet.txt
    1. Assign names to the columns and print the summary of the dataframe.
    2. The author wonders whether the relationship between length and width is the same for boys and girls. Provide two scatterplots, one for boys, one for girls, or one plot with different plotting characters (pch) or colors to distiguish the sexes. Discuss the relationships.