N=200000 bwt=rnorm(N,2100,700) lowbwt=ifelse(bwt<1500,1,0) barplot(table(lowbwt)) p=sum(lowbwt)/N p n=100 amostra=sample(lowbwt,size=n,replace=TRUE) barplot(table(amostra)) pchapeu=sum(amostra)/n pchapeu z=qnorm(0.975) ep=sqrt(pchapeu*(1-pchapeu)/n) li=pchapeu-z*ep ls=pchapeu+z*ep cbind(li,ls) nsim=1000 pchapeu=NULL ep=NULL for (i in 1:nsim){ amostra=sample(lowbwt,size=n,replace=TRUE) pchapeu=c(pchapeu,mean(amostra)) ep=c(ep,sqrt(mean(amostra)*(1-mean(amostra))/n)) } li=pchapeu-z*ep ls=pchapeu+z*ep #probabilidade de cobertura pc=sum(ls>p&lip&li