use "C:\Documents and Settings\User\Desktop\Tutorial1\Table I_1.dta", clear
drop yhat uhat one
desc
sum
regress y x
predict yhat, xb
predict uhat, resid
twoway (scatter y x) (line yhat x)
scatter uhat x
estat vce
g one=1
mkmat one x, matrix(X)
mkmat y, matrix(Y)
matrix b=inv(X'*X)*X'*Y
matrix list b
matrix V=e(V)
matrix list V
matrix varb=vecdiag(V)
matrix list varb
matrix varbt=varb'
matrix list varbt
display sqrt(0.00001957)
display sqrt(827.42155)
display 0.72183434/0.0044238
display -299.59132/28.764936