C Illustrates roundoff error for REAL numbers

C Created:  Joe Zachary, November 15, 1992
C Modified:


      PROGRAM ROUND1

      IMPLICIT NONE
      INTEGER I, N
      REAL PRODUCT, RATIO

      PRINT *, 'Please enter a positive integer value for N'
      READ *, N

      PRODUCT = 1

      DO I = N, 2, -2
         RATIO = REAL(I) / REAL(I-1)
         PRODUCT = PRODUCT * SQRT(RATIO)
      ENDDO

      DO I = N, 2, -2
         RATIO = REAL(I-1) / REAL(I)
         PRODUCT = PRODUCT * SQRT(RATIO)
      ENDDO

      PRINT 30, PRODUCT

 30   FORMAT (F9.7)

      STOP
      END