Answer:
By lot" means that Athens citizens (white males over the age of fifteen) put their name on a stick of wax and put it a container and someones drew out some of the sticks, or drew "lots." And sorry for the short answer.
Step-by-step explanation:
Assembly was set by the Council of Five Hundred, which, unlike the Assembly, was composed of representatives chosen by lot from each of 139 small territorial entities, known as demes, created by Cleisthenes in 507. The number of representatives from each deme was roughly proportional to its population.