I already found part A just need help with B!

The computer-science aptitude score, x, and the achievement score, y (measured by a comprehensive final), were measured for 10 students in a beginning computer-science course. The results were as follows. (Give your answers correct to two decimal places.)
x 22 11 7 18 14 8 22 9 9 6
y 15 24 28 28 33 27 21 30 19 15
(a) Find the equation of the line of best fit.
Y = 26.24 + -.18 x

(b) Find se2.

se2 = sqrt (SSE/n-2))

e = y-yhat

e = 26.24-.18(22) =22.28
x. y. y hat e e^2
22. 15. 22.28. -7.28. 52.9984
11. 24. 24.26 -.26. 0.0676
7. 28. 24.98. 30.2. 9.1204
18. 28. 23. 5. 25
14. 33. 23.72. 9.28. 86.1184
8. 27. 24.8. 2.2. 4.84
22. 21. 22.28 -1.28. 1.6384
9. 30. 24.62. 5.38. 28.9444
9. 19. 24.62. -5.62. 31.5844
6. 15. 25.16. -10.16. 103.226

Sum of e^2 = 343.578

se = sqrt(343.578/8))

se = 6.55342