11. enter a formula in cell e4 to calculate how long each item has been on sale. this is calculated by subtracting the launch date in cell d4 from the data updated date in cell c20. to show the time in years, divide that result by 365. use an absolute reference to the date in cell c20. copy the formula from cell e4 to cells e5: e14.

Local area networks use many of the same network technologies and the internet, only on a smaller scale. devices that access lans are equipped with a network interface that contains circuitry for wireless or wired connections. devices also have a physical address, in addition to the ip addresses acquired from a dhcp server. the most popular wired technology is . the most popular wireless technology is , which can be configured as a(n) or star topology. setting up a lan and configuring its router is fairly easy. the first step is to change the standard to one that is secure. next, create a(n) that uniquely identifies the network by name. it is also important to activate wireless to prevent wireless signals from being intercepted during transmission. a limited-access network can be created for visitors to use. by activating , the router will be able to assign ip addresses to each device that joins the network. to connect to a secure lan that is protected by encryption, an encryption , or password, is required. lans can be used to access data collected by iot devices and the networks that tie these devices together. technologies such as rfid, nfc, bluetooth smart, zigbee, and z-wave offer -power links, essential for battery-powered devices that can’t expend excess amounts of energy transmitting data.