Use R to confirm the results that are given in the book's tables.
I want to see the R-code used for each part. You do not have to 
show all of the output, just the relevant pieces to answer the
questions. Cut and paste relevant R commands and output into a
word processor such as MS Word.


Problem 2
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You can access data for chapter 5 problem 2 using the following:

  source("http://www.uvm.edu/~rsingle/stat221/data/scripts-221.R")
  dat <- bookdata("ch05q02.txt")

2a)  Create a plot for SBP vs. QUET only (not the other 2)
2b5) We will discuss prediction bands on Tuesday.
2b6) also prediction intervals. 
2c)  skip
2d)  skip
2e1) Also plot SBP vs. SMK and add the regression line.  
2e4) Compute a 2-sample T-test comparing SBP where SMK==1 (i.e., dat$SBP[dat$SMK==1] )
     versus SBP where SMK==0, and compare the appropriate statistics from this test to  
     those from the hypothesis test in part 2e3.

NOTE: There are no clarifications for 2b1-2b4, but you still need to do them.

Problem 4    dat <- bookdata("ch05q04.txt")
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4a) Create a plot of DI vs. IQ and add the regression line.
4e) Verify the values for the slope & intercept given in the text
    Find the index of the suspected outlier by looking for an IQ > 130. 
    You can use the following code to find the row index (note the ',' at the end)
      dat[ dat$IQ > 130, ]
    Recall that you can remove an observation (say #3) from an object (called 'obj' here) 
    using obj[-3]. You will need to remove the outlier from the X and Y variable.
4f) Do this by hand and also using R with the outlier removed.    
    
NOTE: There are no clarifications for 4b-4d, but you still need to do them