You are analyzing a linear regression model with 500 observations and one regressor. Explain how you would construct a confidence interval for \(\beta_{1}\) if

a. Assumptions 1 through 4 in Key Concept 19.1 are true but you think assumption 5 or 6 might not be true.

b. Assumptions 1 through 5 are true but you think assumption 6 might not be true. (Give two ways to construct the confidence interval.)

c. Assumptions 1 through 6 are true.