# Required functions: `diff.mean`, `reg.mean`

students=1:10; achieve=c(39,43,21,64,57,47,28,75,34,52)
final=c(65,78,52,82,92,89,73,98,56,75); n=length(x)
class1=data.frame(students,achieve,final)

reg.mean('class1',x=achieve,y=final,N=488,mux=52)


sample=1:10; book=c(10,12,8,26,47,112,36,240,59,167) 
audit=c(9,14,7,29,45,109,40,238,60,170)
cook.the.books=data.frame(sample,book,audit); mux=74
n=length(sample); N=180

diff.mean('cook.the.books',x=book,y=audit,N=N,mux=mux)