PROGRAM BT2_1
      PARAMETER (NMAX=100)
	DIMENSION X(NMAX),X1(NMAX),CHISO(NMAX)
	INTEGER NAM(NMAX), N,N1,I,J
	REAL Q50,Q25,Q75, TB
	REAL ALFA,TRIMEAN,TBHC,IQR,MAD,SHC,YULKED
	OPEN(1,FILE='C:\MASTER\G_TR\BAITAP~1\NEW\BANG1.TXT')
	READ(1,*)
	READ(1,*)
	READ(1,*)N
      READ(1,*)((NAM(I),X(I)), I=1,N)
! TINH TRUNG BINH SO HOC (TB)
	TB = AVER(X,N)
! SAP XEP CHUOI THANH CHUOI TRINH TU (X) VA CHUOI XEP HANG (X1)
	CALL SORT(X,N,X1,CHISO,N1)
	
	  WRITE(*,*) ' CHUOI TRINH TU'
	  WRITE(*,'(10F7.1)') (X(I),I=1,N)
	  WRITE(*,*) ' CHUOI XEP HANG VA CHI SO PHAN TU'
!	  WRITE(*,'(10F6.1)') (X1(I),I=1,N1)
!	  WRITE(*,'(10F6.1)') (CHISO(I),I=1,N1)

	  WRITE(*,*) ' TRUNG BINH SO HOC'
	  WRITE(*,'(" TB = ",F6.1)') TB
! TINH CAC PHAN VI
	CALL QUANTILES(X,N,Q50,Q25,Q75)

	  WRITE(*,*)
	  WRITE(*,'(" TRUNG VI = ",F7.1)') Q50
	  WRITE(*,'(" PHAN VI DUOI = ",F7.1)') Q25
	  WRITE(*,'(" PHAN VI TREN = ",F7.1)') Q75

	  END

      FUNCTION AVER(X,N)
C... CHUONG TRINH NAY TINH TRUNG BINH SO HOC CUA CHUOI
C... DU LIEU VAO LA MANG X DO DAI N CHUA SO LIEU QUAN TRAC
C... CUA BIEN NGAU NHIEN X
      INTEGER N, I
      REAL X(N)		! MANG CHUA SO LIEU BAN DAU
      REAL TMP
      TMP = 0.0
      DO I = 1,N
         TMP = TMP + X(I)
      END DO
      AVER = TMP/REAL(N)
      RETURN
      END

      SUBROUTINE SORT(X,N,X1,CHISO,N1)
!
!  CHUONG TRINH NAY SAP XEP CHUOI THANH CHUOI TRINH TU
!  VA CHUOI XEP HANG
!
! INPUT: + MANG X DO DAI N CHUA CHUOI SO LIEU BAN DAU
!        + N DUNG LUONG MAU
! OUTPUT: + MANG X DO DAI N CHUA CHUOI TRINH TU
!         + MANG X1 DO DAI N1 CHUA CHUOI XEP HANG
!         + MANG CHISO DO DAI N1 CHUA CHI SO CUA CHUOI XEP HANG
!         + N1 SO THANH PHAN TRONG CHUOI XEP HANG
!
	  DIMENSION X(1),X1(1),CHISO(1)
	  INTEGER N,N1,I,J,K
	  REAL TMP
! SAP XEP THANH CHUOI TRINH TU TANG DAN
	  DO I=1,N-1
	  DO J=I+1,N
	     IF (X(J).LT.X(I)) THEN
	        TMP=X(J)
			X(J)=X(I)
			X(I)=TMP
		 ENDIF
	  ENDDO
	  ENDDO
! XAC DINH CAC THANH PHAN CUA CHUOI XEP HANG
	  N1=1
	  I=1
	  X1(N1)=X(I)
	  CHISO(N1)=REAL(I)
  10  I=I+1
      IF (I.GT.N) GOTO 100
	  IF (X(I).NE.X(I-1)) THEN
	     N1=N1+1
		 X1(N1)=X(I)
	  ENDIF
      GOTO 10
 100  CONTINUE
!  TINH CHI SO CUA CAC THANH PHAN TRONG CHUOI XEP HANG
	  DO J=1,N1
         K=0
		 CHISO(J)=0.0
		 DO I=1,N
            IF (X(I).EQ.X1(J)) THEN
			   K=K+1
			   CHISO(J)=CHISO(J)+REAL(I)
			ENDIF
		 ENDDO
		 CHISO(J)=CHISO(J)/REAL(K)
	  ENDDO
      RETURN
	END

	FUNCTION Q05(X,N)
!
! HAM NAY TINH TRUNG VI CUA CHUOI X
! INPUT: + X LA MANG SO LIEU DA SAP XEP THANH CHUOI TRINH TU
!        + N LA DO DAI CUA X (DUNG LUONG MAU)
! OUTPUT: + TRUNG VI CUA CHUOI
!
      DIMENSION X(N)
	INTEGER N,I,NC
	  NC=N/2
	  IF (MOD(N,2).EQ.0) THEN
		 Q05=(X(NC)+X(NC+1))/2.0
	  ELSE
	     Q05=X(NC+1)
	  ENDIF
	  RETURN
	  END

	SUBROUTINE QUANTILES(X,N,Q50,Q25,Q75)
!
! CHUONG TRINH NAY TINH CAC PHAN VI CHINH CUA CHUOI X DO DAI N
!
! INPUT: + X MANG CHUA CHUOI SO LIEU DA SAP XEP TRINH TU
!        + N DUNG LUONG MAU
! OUTPUT: + TRUNG VI Q50
!         + CAC PHAN VI DUOI VA TREN Q25, Q75
! FUNCTION/SUBROUTINE DUOC GOI TOI: Q05(X,N)
!
      DIMENSION X(N), X1(N)
	INTEGER N,I,NC1,NC2,NT,J
	REAL Q50,Q25,Q75
	  Q50=Q05(X,N)
	  NT=N
	  NC1=NT/2
	  IF (MOD(NT,2).EQ.0) THEN
	     NC2=NC1+1
	  ELSE
	     NC1=NC1+1
		 NC2=NC1
	  ENDIF
	  DO I=1,NC1
	     X1(I)=X(I)
	  ENDDO
	  Q25=Q05(X1,NC1)
	  J=0
	  DO I=NC2,N
	     J=J+1
	     X1(J)=X(I)
	  ENDDO
	  Q75=Q05(X1,NC1)
	  RETURN
	  END