STAT 220: Basic Statistics for Quantitative Students

Spring 2006

Assignment due Feb. 3

Type or write your answers to the following questions to turn in on Feb. 3 in class. A couple of these questions have answers in the back of the book. Feel free to use the answers to guide you if you wish; however, keep in mind that you will be assumed to know how to do all of these questions on an exam.

  1. Write up answers to Exercises 10.14, 10.18, 10.33, 10.42, 11.22, 11.43
  2. Write up an answer to Exercise 10.52. Since you should already have a cleaned-up version of the GSS-93 dataset from the previous assignment, you can simply use that dataset. Use the 'table' function in R to extract the required summary statistics, then show all of your work by hand.
  3. Write up an answer to Exercise 11.71. There is an already-cleaned-up version of this dataset called UCDavis2.na.txt that you may use if you wish. In fact, you can read it directly into R using this command: 
    ucd = read.table("http://www.stat.psu.edu/~dhunter/220/files/datasets/ascii/UCDavis2.na.txt",
    header=TRUE)
    After you have created the ucd object, check that it has been correctly loaded by typing names(ucd) and verifying that the names of the columns are correct. Next, use attach(ucd) to create a new temporary vector out of each column in the ucd dataset. Finally, use the table function to extract the summary information required to complete the exercise. Show all of your work after you obtain this information.
As always, email me if you have questions.