*Insert the directory path in which the BlankWithId500.dta file exists:
cd "C:\"
use "BlankWithId500.dta", clear
gen x=rnormal()
gen y=rnormal()
*gen y=5+4*x+rnormal(0,3)

gen xy=x*y
egen sumXY=total(xy)
egen sumX=total(x)
egen sumY=total(y)
gen xsqr=x^2
gen ysqr=y^2
egen sumXsqr=total(xsqr)
egen sumYsqr=total(ysqr)
display (_N*sumXY-sumX*sumY)/sqrt((_N*sumXsqr-sumX^2)*(_N*sumYsqr-sumY^2))

pwcorr y x, sig
scatter y x