College tuition has risen at a pace faster than inflation for more than two decades, according to an article in USA Today. The following data indicate the average college tuition (in 2003 dollars) for public colleges:

Period 1983–1984 1988–1989 1993–1994 1998–1999 2003–2004 2008–2009 Public 2,074 2,395 3,188 3,632 4,694 5,652

a. Produce a time-series plot of these data. Indicate the time-series components that exist in the data.

b. Provide a forecast for the average tuition for public colleges in the academic year 2013–2014. (Hint:
One time-series time period represents five academic years.)

c. Provide an interval of plausible values for the average tuition change after five academic periods have gone by. Use a confidence level of 0.90.