PROGRAM BT2_6
	PARAMETER (NMAX=100)
	DIMENSION X(NMAX)
	INTEGER NAM(NMAX),N,I,K
	REAL TB,DX,SX,AX,EX,CV,RANGE,XMAX,XMIN
	  
	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)

	TB=AMMGOC(X,N,1)
	DX=AMMTAM(X,N,2)
	SX=SQRT(DX)
	AX=AMMTAM(X,N,3)/(DX*SX)
	EX=AMMTAM(X,N,4)/(DX*DX)-3.0
	CV=SX/TB
	XMAX=X(1)
	XMIN=X(1)
	DO I=2,N
		IF (X(I).LT.XMIN) XMIN=X(I)
		IF (X(I).GT.XMAX) XMAX=X(I)
	ENDDO
	RANGE=XMAX-XMIN

	WRITE(*,*)' CAC DAC TRUNG CO BAN TINH THEO PHUONG PHAP TRUC TIEP'
	
	WRITE(*,'("TRUNG BINH:       ",F20.3)') TB
	WRITE(*,'("PHUONG SAI:       ",F20.3)') DX
	WRITE(*,'("DO LECH CHUAN:    ",F20.3)') SX
	WRITE(*,'("DO BAT DOI XUNG:  ",F20.3)') AX
	WRITE(*,'("DO NHON:          ",F20.3)') EX
	WRITE(*,'("HE SO BIEN THIEN: ",F20.3)') CV
	WRITE(*,'("BIEN DO:          ",F20.3)') RANGE
	WRITE(*,'("DUNG LUONG MAU:   ",I20)') N
	
	END


	  FUNCTION AMMGOC(X,N,K)
!
! HAM NAY TINH MOMEN GOC BAC K CUA CHUOI SO LIEU
! INPUT: + X MANG SO LIEU BAN DAU DO DAI N
!        + N DUNG LUONG MAU
!        + K BAC CUA MOMEN
! OUTPUT: MOMEN GOC BAC K
!
      DIMENSION X(N)
	  INTEGER N,K,I
	  REAL TMP
	  TMP=0.0
	  DO I=1,N
	     TMP=TMP+X(I)**K
	  ENDDO
	  AMMGOC=TMP/REAL(N)
	  RETURN
	  END

	  FUNCTION FAC(N)
! TINH N! (N GIAI THUA)
	  REAL TMP
	  IF (N.LT.0) THEN
	     WRITE(*,*)' INVALID NUMERIC INPUT IN FAC FUNCTION'
		 STOP
	  ELSE IF (N.EQ.0.OR.N.EQ.1) THEN
	     FAC=1.0
		 RETURN
	  ELSE
	     TMP=1.0
		 DO I=2,N
	        TMP=TMP*REAL(I)
		 ENDDO
		 FAC=TMP
		 RETURN
	  ENDIF
	  END

      FUNCTION COMBIN(N,K)
! TINH TO HOP CHAP K CUA N
! FUNCTION/SUBROUTINE DUOC GOI TOI: FAC(N)
	  IF (N.LT.0.OR.K.LT.0.OR.N.LT.K) THEN
	     WRITE(*,*)' INVALID NUMERIC INPUT IN COMBIN FUNCTION'
		 STOP
      ELSE 
         COMBIN=FAC(N)/FAC(K)/FAC(N-K)
	     RETURN
	  ENDIF
	  END

	  FUNCTION AMMTAM(X,N,K)
! HAM NAY TINH MOMEN TRUNG TAM BAC K TU CHUOI SO LIEU X
! INPUT: + X MANG SO LIEU BAN DAU DO DAI N
!        + N DUNG LUONG MAU
!        + K BAC CUA MOMEN
! OUTPUT: MOMEN TRUNG TAM BAC K
! FUNCTION/SUBROUTINE DUOC GOI TOI: AMMGOC(X,N,K), COMBIN(N,K)
	  DIMENSION X(N)
	  INTEGER N,K,I
	  REAL TMP,TB
	  TB=AMMGOC(X,N,1)
	  TMP=0
	  DO I=0,K
	     TMP=TMP+(-1)**I*COMBIN(K,I)*TB**I*AMMGOC(X,N,K-I)
	  ENDDO
	  AMMTAM=TMP
	  RETURN
	  END