dax correction

Hi JothiG 

Replace your final multiplication with a SUMX that multiplies per row, inside the same filters:

4_Cur_yr_cost_amt_pur =
VAR SelectedYear = MAX('yarn data'[Stock_finyear])
VAR _month_max = CALCULATE(
    MAX('yarn data'[month_sorter]),
    ALL('yarn data'),
    'yarn data'[Stock_finyear] = SelectedYear
)
VAR _month = SELECTEDVALUE('yarn data'[month_sorter])
VAR _month_calc = IF( ISBLANK(_month), _month_max, _month )

RETURN
CALCULATE(
    SUMX(
        'yarn data',
        'yarn data'[Qty] * 'yarn data'[rate]
    ),
    'yarn data'[Stock_finyear] = SelectedYear,
    'yarn data'[month_sorter] = _month_calc
)