mysummary=function(bf$age) {s1=mean(bf$age) s2=sd(bf$age)
                            s3=quantile(bf$age,probs=c(0.25,0.50,0.75))
                            s4=IQR(bf$age) summary=list(mean=s1,sd=s2,quantile=s3,IQR=s4)
                            return(summary)}