Use the following information for the Exercises $3-7$ below. $($Algo$)$

$[$The following information applies to the questions displayed below.$]$

Laker Company reported the following January purchases and sales data for its only product. For specific identification, ending inventory consists of $270$ units from the January $30$ purchase, $5$ units from the January $20$ purchase, and $10$ units from beginning inventory.

$\backslash$table$[[\backslash$table$[[$Date$],[$January $1],[$January $10],[$January $20],[$January $25],[$January $30]],\backslash$table$[[$Sales$],[$Purchase$],[$Sales$]],100$ units,@$,$$$10\mathrm{.}00=,1,000,145$ units,@$,$$$20\mathrm{.}00$