```
Program g07cafe
! G07CAF Example Program Text
! Mark 27.0 Release. NAG Copyright 2019.
! .. Use Statements ..
Use nag_library, Only: g07caf, nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Real (Kind=nag_wp) :: clevel, df, dl, du, prob, t, xmean, &
xstd, ymean, ystd
Integer :: ifail, nx, ny
Character (1) :: equal, tail
! .. Executable Statements ..
Write (nout,*) 'G07CAF Example Program Results'
Write (nout,*)
! Skip heading in data file
Read (nin,*)
! Read in the sample sizes, means and standard deviations
Read (nin,*) nx, xmean, xstd
Read (nin,*) ny, ymean, ystd
! Display data
Write (nout,*) 'Sample X'
Write (nout,99996) ' Sample size = ', nx
Write (nout,99995) ' Mean =', xmean
Write (nout,99995) ' Standard deviation =', xstd
Write (nout,*)
Write (nout,*) 'Sample Y'
Write (nout,99996) ' Sample size = ', ny
Write (nout,99995) ' Mean =', ymean
Write (nout,99995) ' Standard deviation =', ystd
d_lp: Do
! Read in the type of statistic and CI required
Read (nin,*,Iostat=ifail) clevel, tail, equal
If (ifail/=0) Then
Exit d_lp
End If
! Calculate statistic
ifail = 0
Call g07caf(tail,equal,nx,ny,xmean,ymean,xstd,ystd,clevel,t,df,prob, &
dl,du,ifail)
! Display results
Write (nout,*)
If (equal=='E' .Or. equal=='e') Then
Write (nout,*) 'Assuming population variances are equal.'
Else
Write (nout,*) 'No assumptions about population variances.'
End If
Write (nout,*)
Write (nout,99999) 't test statistic = ', t
Write (nout,99998) 'Degrees of freedom = ', df
Write (nout,99997) 'Significance level = ', prob
Write (nout,*)
Write (nout,99999) 'Difference in means'
Write (nout,99999) ' Value = ', xmean - ymean
Write (nout,99999) ' Lower confidence limit = ', dl
Write (nout,99999) ' Upper confidence limit = ', du
Write (nout,99999) ' Confidence level = ', clevel
End Do d_lp
99999 Format (1X,A,F10.4)
99998 Format (1X,A,F8.1)
99997 Format (1X,A,F8.4)
99996 Format (1X,A,I5)
99995 Format (1X,A,E11.4)
End Program g07cafe
```