# This R code deals with the two-sample situation considered in 
# Sec. 8.3 of E&T.

Treatment <- c(94, 197, 16, 38, 99, 141, 23)
Control <- c(52, 104, 146, 10, 51, 30, 40, 27, 46)

set.seed(321)

Tbss <- matrix( sample( Treatment, size=1400*length(Treatment), replace=T ), nrow=1400 )
Treps <- apply( Tbss, 1, mean )
Cbss <- matrix( sample( Control, size=1400*length(Control), replace=T ), nrow=1400 )
Creps <- apply( Cbss, 1, mean )
Diffreps <- Treps - Creps

# I'm curious as to how nonnormal the difference replicates appear to be.
qqnorm(Diffreps, datax=TRUE)

# Here's the usual estimated standard error:
sqrt( var(Treatment)/length(Treatment) + var(Control)/length(Control) )

# Here's the bootstrap estimate of standard error as decribed in E&T:
sd(Diffreps)

# Here's my alternative bootstrap estimate of standard error:
sqrt( var(Treps) + var(Creps) )