Sir easy class 2 math tay, standard deviation (sigma p) formulate apni ep^2 dicen but man bosanor somoy to opore power den nai...karon ta ki sir plz reply diyen.
Vai calculator ar mood button ace oita double chap diben,, trpor 2 chapben,,trpor 1 chapben,, trpor shift chapbn, trpor 3 chapben trpor 1 chapben tai dekhben display te n ( asche...then d1 ar j point soho man ta ace okhane bosaia diye equal chaplei result peye jaben