Final answer:
A data throughput test is a test that should be performed during a site survey to enable the design engineer to understand and control the user's experience on the wireless LAN.
Step-by-step explanation:
During a site survey on a wireless LAN, one of the important tests to perform is a data throughput test. This test measures the amount of data that can be transmitted and received over the wireless network in a given time period. By conducting this test, the design engineer can understand and control the user's experience on the wireless LAN by ensuring that the network has sufficient bandwidth and can handle the expected data load.