A researcher would like to investigate whether or not college education can affect the IQ of students. She gathers 9 students and has them all take the IQ tests in their first and last years of college to test this hypothesis using an alpha level of .01. Below are the data:

1styear	4thyear
110	90
120	98
100	100
90	110
124	100
102	120
110	110
123	120
105	110

Find the critical value: +-_____