Please explain how to get to that answer. thanks

Salem Corp uses a periodic inventory system. During June, 740 units were sold. Use the following information to calculate the amount allocated to ending inventory using FIFO during June: Units Unit Cost Total Cost 6/1 Inv. 255 $7 $1,785 6/14 Purch. 370 $8 $2,960 6/25 Purch. 335 $9 $3,015 Total 960 $7,760 $1,980 $5,780 $6,220 x $1,540