#Wilcoxon Signed Rank Test

#Data for SBP in OC and non-OC users
 sbp1 = c(115, 112, 107, 119, 115, 138, 126, 109, 104, 115)
 sbp2 = c(128, 115, 106, 128, 122, 145, 132, 109, 102, 117)
 diff   = sbp1 - sbp2

 wilcox.test(diff, correct=F, exact=F)   #OR#
 wilcox.test(sbp1, sbp2, paired=TRUE, correct=F, exact=F )


 n=9   #number of non-zero differences
 V=3.5
 mu.v = n*(n+1)/4
 sd.v = sqrt( (n*(n+1)*(2*n+1))/24 )
 z.s = (V - mu.v)/sd.v
 pnorm(z.s)