Refer to Exercise 14.51; 90%.
Procedure 14.2
Regression t-Interval Procedure
Purpose To find a confidence interval for the slope, β1, of the population regression line
Assumptions The four assumptions for regression inferences
Step 1: For a confidence level of 1 − α, use Table IV to find tα/2 with df = n − 2.
Step 2: The endpoints of the confidence interval for β1 are β1 ± tα/2 .se/√Sxx
Step 3: Interpret the confidence interval.