SUBROUTINE TTAFF(NF,T)
C	T-TEST FUER PA=95% , ZWEISEITIGER BEREICH
	DIMENSION BT(19)
	BT(1)=12.706
	BT(2)=4.303
	BT(3)=3.182
	BT(4)=2.776
	BT(5)=2.571
	BT(6)=2.447
	BT(7)=2.365
	BT(8)=2.306
	BT(9)=2.262
	BT(10)=2.228
	BT(11)=2.201
	BT(12)=2.179
	BT(13)=2.160
	BT(14)=2.145
	BT(15)=2.131
	BT(16)=2.120
	BT(17)=2.110
	BT(18)=2.101
	BT(19)=2.093
	IF(NF-19)12,12,23
12	T=BT(NF)
	RETURN
23	F=FLOAT(NF)
	T=1.9596+2.4/F+2.6/(F*F)+2.0/(F*F*F)
	RETURN
	END