Home work 2: Stat 530 Due Feb 5: (20 points)
1. Consider the data set on age and cholesterol given in our class website names Hw1-2016.xls.
Same data set you used for HW 1. Answer the questions based on this data set:
a. Determine least squares’ equation that can be used for predicting Cholesterol.
b. Give 95% confidence intervals for the change in Cholesterol for a unit change in age.
c. Is this rate (in b) significantly greater than 0. Use alpha = .05.
d. Do the results in (b) and (c) agree? Should they?
e. Use your model to predict Cholesterol when age is 45
f.
Provide 95% confidence intervals for e.
g. Provide 95% prediction intervals for (e)
h. Comment on your findings in (f) and (g).
2. Sketch a graph that shows a negative relationship between y and x. Give an example of a
situation where you might see this relationship.
3. Say TRUE or FALSE with reason: The least square estimates, beta_1_hat and beta_0_hat are
independent of each other.