Nine pairs of universities were matches as closely as possible according to size, type of administrative control, and location. In each pair one institution had a faculty organized for collective...

Nine pairs of universities were matches as closely as possible

according to size, type of administrative control, and location.

In each pair one institution had a faculty organized for collective bargaining, while the other was not so organized. The

average difference in faculty compensation was $1600, with a

standard deviation of the differences of $500. The average

difference favored the organized institutions. Is the difference significant (a = 0.05)? What is a 95% confidence interval

for the difference?