Name:________________________
R Lab 7 – Regression (continued)
Analyze the relationship between wrist size and circumference of the abdomen by using the data
contained with the 'fat' (UsingR) dataset.
1.
2.
3.
4.
Is a linear model appropriate?
What is the equation of the least squares line?
What proportion of the observed variation in 'abdomen' can be explained through 'wrist'?
In the summary of your linear model what are the p-values for the t statistic associated with
'wrist' and the f statistic for the model? Why are they so small? Can we expect them to give the
same value? Why are they useful?
5. Is there strong evidence that the true slope is greater than 3? Use the estimate for the slope and
its standard error to devise a (one sided) test. Use the 68 95 99.7 rule for normal data.
6. Construct a confidence interval for the true, average abdomen circumference of individuals with
wrist size of 17cm.
7. Construct a prediction interval for the abdomen circumference of the next individual with wrist
size of 17cm.