Mark Wickens

10 MODE8:DIM:GOSUB500:c$=CHR$(5):p=0
20 CLS:PRINT"Percentage points   N(0,1²)";
30 LOCATE0,1:PRINTc$;"p=";p;"?";:INPUT@10;p:LOCATE0,0:IFp=<0 ORp>=1 THEN30
60 LOCATE0,1:PRINTc$;".....";
70 sr=0:GOSUB"LIB0:S6410":GOSUB500:IFsr THEN*
75 IFx THENx=ROUND(x,LOG(ABSx)-6)
80 PRINTc$;"x=";x;:z$=INPUT$(1,@):GOTO30
500 ONERRORGOTO510:RETURN
510 IFERR=1 THENCLS:ONERRORGOTO0
520 IFERL=30 THENRESUME30
530 LOCATE0,1:PRINTc$;"not found";:z$=INPUT$(1,@):RESUME20