A regression analysis is conducted with 25 observations.
a. What is the df value for inference about the slope β?
b. Which two t test statistic values would give a P-value of 0.05 for testing H0: β = 0 against Ha: β ≠ 0?
c. Which t -score would you multiply the standard error by in order to find the margin of error for a 95% confidence interval for β?