Answer:
Closing Units =  (710 units - 490 units)= 220 units
a) FIFO : closing inventory = $14,040
    Mar 18 purchase 20 *$62 =$1,240
   Mar 25 purchase 200 *$64 = $12,800
b) LIFO : closing inventory = $12,780
 Mar 1 opening = 90 * $52 =$4,680
 Mar 18 purchase = 110 * $62 = $6,820
 Mar 25 purchase = 20*$64 =1,280
c) Weighted Average Method (WAM) :
WAM= (Opening cost + purchases cost)/(opening units +units purchased)
        = ($7,800+$14,250)/(150+250) = $55.125 cost before Mar 9 sale
WAM(after the first sale) = ($4,961.25 +$6,820 + $12,800)/(90+110+200)
                                         = $61.45
Closing Inventory = $61.45*220 =$13,519
d) Specific Identification :Closing Inventory = $13,070
 Mar 01 opening = 60 *$52 =$3,120
 Mar 5 Purchase = 30*$57 =$1,710
 Mar 18 Purchase = 40*$62 =$2,480
 Mar 25 Purchase = 90*$64 =$5,760
Explanation:
The Question is incomplete. I have provided the missing part of the question below.
Date	Activities	Units Acquired at Cost	Units Sold at Retail
Mar.	1  Beginning inventory  150	units  $52.00/unit    
Mar.	5  Purchase  250	units  $57.00/unit    
Mar.	9  Sales      310	units  $87.00/unit
Mar.	18  Purchase  110	units  $62.00/unit    
Mar.	25  Purchase  200	units  $64.00/unit    
Mar.	29  Sales      180	units  $97.00/unit
      Totals  710	units  	490	units