qdat1()
 dat <- qdat2()
 head(dat)

#----------------
# static data from earlier
#file <- "http://www.uvm.edu/~rsingle/stat211/data/extra/pulse_old.txt"
#dat <- read.table(file, header=T, na.strings=c("NA",".")) 
#head(dat)

#----------------
#(begin XXXX)  default T-test
 t.test(dat$before, dat$after, alternative="less")

 par(mfrow=c(2,2))
 boxplot(dat$before)
 boxplot(dat$after)
#(end XXXX)  default T-test








#----------------
# paired T-test
 t.test(dat$before, dat$after, alternative="less", paired=TRUE)

#check assumptions on the differences 
 plot(dat$before, dat$after) #check if pairing was effective
 dat$diff = dat$before - dat$after
 boxplot(dat$diff, main="Boxplot of differences") 

#Note: the other way to specify the test is as a 1-sample T-test on the differences 
 t.test(dat$diff, alternative="two.sided") #get a 95%CI for mu_difference