Show your work for any parts where you are aske dto compute BY HAND.

I want to see the R-code used for each part. DO NOT 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. 

DO NOT INCLUDE OUTPUT THAT YOU DO NOT REFER TO OR USE IN THE PROBLEM, 
otherwise points will be deducted.


Problem 6   dat <- bookdata("ch05q06.txt")
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6a) Create a scatterplot and add the regression line in R.
6d) Compute the interval BY HAND (based on summary statistics from R).
6f) Also, compute BY HAND a 95% confidence interval for the conditional mean at 
    AGE=10 (based on summary statistics from R).
    

Problem 8    dat <- bookdata("ch05q08.txt")
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NOTE: part (g) is an added question.

8a) Create a scatterplot and add the regression line in R.
    Use the multifig(2,2) command for this problem as there
    will be 4 plots. Place the 4 plots under part (a) so they are easy 
    to find.
8d) Carry out the test BY HAND using a T statistic and compute a p-value
    for the test. 
8e) These are plots 2 & 3. 
8f) Answer this question by computing the specific interval (confidence or prediction, 
    you decide) at Xo=2.75. Show your interval and justify your conclusion. 
8g) Use Tukey's Rule of the Bulge to identify a transformation of your Y-variable so 
    that the assumptions of the linear model are satisfied better. You may need to try
    more than one transformation before things look better. Create a scatterplot with 
    the estimated regression line and describe how it better fits the transformed data 
    than the line in part (a).