What are three different types of written intradepartmental or interdepartmental communication? What are three types of written communication used between different companies or the public?

Lauer corporation uses the periodic inventory system and has provided the following information about one of its laptop computers: date transaction number of units cost per unit 1/1 beginning inventory 210 $ 910 5/5 purchase 310 $ 1,010 8/10 purchase 410 $ 1,110 10/15 purchase 255 $ 1,160 during the year, lauer sold 1,025 laptop computers. what was cost of goods sold using the lifo cost flow assumption?