a. In Exercise 11.38a, you fit a straight-line model relating cost (y) to JIF (x). Find and interpret a 95% confidence interval for the slope of the line.
b. In Exercise 11.38b, you fit a straight-line model relating cost (y) to number of citations (x). Find and interpret a 95% confidence interval for the slope of the line.
c. In Exercise 11.38c, you fit a straight-line model relating cost (y) to RPI (x). Find and interpret a 95% confidence interval for the slope of the line.
For Information: Refer to the Geoforum (Vol. 37, 2006) study of whether the price of a geography journal is correlated with quality. Exercise 11.38.