Program for calculation of critical t values based on following document
http://www.namirsham.../NEW/InvPDF.pdf
The 5 values of 2 tail alpha is used.
Norm 1:ClrVar:Cls:↵
"Chose alpha: 0.2→1:0.15→2:0.1→3:0.05→4:0.025→5"?→A↵
"DoF="?→F↵
If A=1↵
Then e^(0.248069936+0.660674÷F+0.226537)÷F²→T↵
Cls:Locate 1,1,"alpha=":Locate 7,1,A-0.8◢↵
Locate 1,2,"DoF=":Locate 5,2,F◢↵
Locate 1,3,"TVAL=":Locate 6,3,T◢↵
Goto 5↵
Else Goto 1↵
IfEnd↵
Lbl 1↵
If A=2↵
Then e^(0.364320592+0.767873÷F+0.308868÷F²)→T↵
Cls:Locate 1,1,"alpha=":Locate 7,1,A-1.85◢↵
Locate 1,2,"DoF=":Locate 5,2,F◢↵
Locate 1,3,"TVAL=":Locate 6,3,T◢↵
Goto 5↵
Else Goto 2↵↵
IfEnd↵
Lbl 2↵
If A=3↵
Then e^(0.497661825+0.925738÷F+0.445297÷F²)→T↵
Cls:Locate 1,1,"alpha=":Locate 7,1,A-2.9◢↵
Locate 1,2,"DoF=":Locate 5,2,F◢↵
Locate 1,3,"TVAL=":Locate 6,3,T◢↵
Goto 5↵
Else Goto 3↵
IfEnd↵
Lbl 3↵
If A=4↵
Then e^(0.672951400+1.208789÷F+0.734348÷F²)→T↵
Cls:Locate 1,1,"alpha=":Locate 7,1,A-3.95◢↵
Locate 1,2,"DoF=":Locate 5,2,F◢↵
Locate 1,3,"TVAL=":Locate 6,3,T◢↵
Goto 5↵
Else Goto 4↵
IfEnd↵
Lbl 4↵
If A=5↵
Then e^(0.807141675+1.503440÷F+1.093993÷F²)→T↵
Cls:Locate 1,1,"alpha=":Locate 7,1,A-4.975◢↵
Locate 1,2,"DoF=":Locate 5,2,F◢↵
Locate 1,3,"TVAL=":Locate 6,3,T◢↵
Lbl 5↵
"STOP"↵
Example: alpha = 0.2
DoF= 40
t-value = 1.303
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alpha = 0.025
DoF = 14
t-value = 2.509