220 "L" CLEAR : RESTORE 228: READ D: DIM A#(D),B#(D),C#(D),D#(D): FOR A=1 TO D: READ A#(A),B#(A): NEXT A
  221 INPUT "x=";F#: FOR C=1 TO D: IF C=D THEN 226
  222 FOR A=C+1 TO D: IF B#(A)=D#(A-1) THEN 227
  223 E#=(B#(A)-B#(A-1))/(B#(A)-D#(A-1)):E#=A#(A)-A#(A-C)-E#*(F#-A#(A-C))
  224 IF E#=0 THEN 227
  225 C#(A)=B#(A)+(F#-A#(A))*(B#(A)-B#(A-1))/E#: NEXT A
  226 FOR B=C TO D:D#(B)=B#(B):B#(B)=C#(B): NEXT B: NEXT C: PRINT "x=";F#: PRINT "f(x)=";C#(D): END 
  227 PRINT "Nenner->0": END 
  228 DATA 5
  229 DATA -.3,-17.905
  230 DATA -.1,-14.535
  231 DATA .5,-5.625
  232 DATA .7,-2.255
  233 DATA 1.1,6.525