Sarasota Corp. sells a snowboard, WhiteOut, that is popular with snowboard enthusiasts. Presented below is information relating to Sarasota Corp.$\text{'}$s purchases of WhiteOut snowboards during September. During the same month, $100$ WhiteOut snowboards were sold at $$170$ each. Sarasota Corp. uses a periodic inventory system.

$\backslash$table$[[$Date$,$Explanation,Units,Unit Cost,Total Cost$],[$Sept$.1,$Inventory,$21,$$$100,$$$2,100],[$Sept$.12,$Purchases,$37,106,3,922],[$Sept$.19,$Purchases,$20,1,2,200],[$Sept$.26,$Purchases,$41,112,4,592],[$Totals$,119,,$$$12,814]]$

$($a$)$