# Author: Adolfo J. Rumbos
# Date: 9/3/2008
#

# This R code performs a randomization test on a subset of the Westvaco 
# data found on page 5 of Statistics in Action by Watkins, Sheaffer and 
# Cobb.
#
# The subset consists of the 10 hourly workers involved the second of
# the five rounds of layoffs.  Three of the 10 workers were laid off  
# in that round. 
#
# The 10 hourly workers involved in the 2nd round of layoffs are entered into
# a vector called hourly2
#



hourly2 <- c(25,38,56,48,55,64,55,55,33,35)



Nsamples <- 1000 	# Nsamples is the number of samples drawn

#
# Nsamples random samples of size 3, without replacement, 
# from hourly2 and their averages are computed and stored in a vector
# denoted Xbar
#



Xbar <-  mean(sample(hourly2,3,replace=F))		
				# sets initial value of x_bar 

l <- Nsamples -1  # we need Nsamples - 1 more samples

 for (i in 1:l) # Sets up a loop from 1 to Nsamples

 {			# Begins body of loop

 Xbar <- c(Xbar, mean(sample(hourly2,3,replace=F)))
			# creates vector of average ages of laid off workers

 }			# End of loop