Try

in "OT"

im M2

=SUM((([@[Monthly Base]]+[@Shift]+[@Stipend])/173.333)*IF([@[Earn ID]]="OTPR",1.5,1))

in "STIPENDS"

in N2

=SUMPRODUCT((Stipend_Type[Amount])*(Stipend_Type[Stipend Type]=Stipends[@[Stipend Name]:[Special Assignment 3]]))