Run different calculation for each value chosen from the listbox

Calculation script

  global popVal
  
    
    cg=(0.2*popVal)./(std(Bf)*6);
    cgk=(0.1*popVal-sqrt(((Betaavg-Refx).*(Betaavg-Refx))))./(3*std(Bf));
    
MASTER{15,MASTERcount}=cg;
MASTER{16,MASTERcount}=cgk;
    

How do I store different values on to my handle everytime I choose an answer from my listbox?

Matlab gui

function popupmenu13_Callback(hObject, eventdata, handles)

contents = cellstr(get(hObject,'String'));
popChoice= contents(get(hObject,'Value'));
assignin('base','popChoice',popChoice)

 global popVal
 
if (strcmp(popChoice,'Select Beta Tolerance'))
    popVal=0;
elseif (strcmp(popChoice,'5°'))
    popVal=5;
elseif (strcmp(popChoice,'6°'))
    popVal=6;
elseif (strcmp(popChoice,'7°'))
    popVal=7;
elseif (strcmp(popChoice,'8°'))
    popVal=8;
elseif (strcmp(popChoice,'9°'))
    popVal=9;    
elseif (strcmp(popChoice,'10°'))
    popVal=10;   
end
assignin('base','popVal',popVal)