10 CLS
20 PRINT "POISSON DISTRIBUTION"
30 DEFDBL A-Z  : DEFSNG I,J,K
40 PRINT 
50 PRINT "(TO END PROGRAM ENTER 0)" 
60 PRINT "CALCULATED FREQUENCY"; 
70 INPUT L 
80 IF L=O THEN 200  
90 PRINT "TEST FREQUENCY"; 
100 INPUT X 
110 A=1 
120 FOR I=1 TO X 
130 A=A*I 
140 NEXT I 
150 A=LOG(A)
160 A=EXP(-L+X*LOG(L)-A)
170 PRINT "PROBABILITY OF";X;"OCCURRENCES=";A 
180 PRINT 
190 GOTO 60   
200 END