# 26
X <- read.csv("schizo.csv", header = TRUE)     

 Y <- X[,1] - X[,2]
 t.test(Y)

 plot(X[,1], X[,2])  # evidence that the paired design seems to work

 Ylog <- log(X[,1]/X[,2])
 t.test(Ylog)      # p-value is somewhat smaller compared to the untransformed case 

 print( CImed <- exp(t.test(Ylog)$conf.int)  )

# 27
 wilcox.test(Ylog)    # the results are of course similar to the Book's section 4.4.2
 wilcox.test(Y)       
  # the results of the untransformed test are identical, so we can pick the one that is more symmetrical
  # which would be neither in this particular case ;) 

# 29 

 exer <- c(9, 9.5, 9.5, 9.75, 10, 13) 
 noex <- c(9, 11.5, 11.5, 12, 13, 13.25)

 wilcox.test(exer, noex)