Overall, professor salaries barely budged during past year, the Chronicle says, noting that on average, salaries for full-time faculty rose 1.8% in the 2011-12 school year, while inflation was 3%. Tuition, meanwhile, has increased dramatically.
Inferential Statistics. Inferential statistics is concerned with making predictions or inferences about a population from observations and analyses of a sample. That is, we can take the results of an analysis using a sample and can generalize it to the larger population that the sample represents.
Usually, the known value is a population mean. The dependent variable is normally distributed. Null: There is no significant difference between the sample mean and the population mean. Alternate: There is a significant difference between the sample mean and the population mean. Go to Analyze menu, choose Compare Means, then One-Sample T Test. Move the dependent variable into the  Test Variables  box.