Here is some information about a professor salary index (PSI)
(a) Calculate the unknown quantities a, b, c, d, e in the table.
(b) What is the base year of the PSI? How did you determine it?
(c) Given the data for the PSI, calculate the average annual price increase in salaries paid to professors for between 2004 and 2008 and between 2006 and 2011.