parameter(max=100000)
	real*4 x(max)

* read the data into x

	open(1,file='/home/sgao/demo/07_f77/a.dat')
	do i=1,max
	read(1,*,end=111) x(i)
	enddo
111	close(1)

	npts=i-1

** Now get the mean

	av=0.0
	do i=1,npts
	av=av+x(i)
	enddo

	av=av/npts

	print*,'The mean is ', av,'; total us ', av*npts

	stop
	end