Suppose 3DR was giving away a FREE trip to Hawaii for attendees that voluntarily inquired about more information on 3DR products/services during the event. Obviously, 3DR could use the same Marketing Data collected by voluntary attendees that decided to scan their RFID wristbands. In this case, it would be wise for 3DR to know what the chance of each attendee category was in the table to be randomly selected. Here’s how 3DR can calculate this.
Given the Executive Management category from the table, 3DR would use this statistical formula P(EM) = Total # Executive Management attendees/Total # attendees. For this, 3DR would take the total number of recorded Executive Management attendees (i.e. 230) and divide by total number of recorded attendees (i.e. 584); P(EM) = 230/584 = .393. As a result, the probability of selecting an attendee from the:
Executive Management category would be 39.3%,
Project Manager (P(PM) = 227/584 = .388 = 38.8%),
Engineering/Technical Lead (P(ETL) = 86/584 = .147 = 14.7%), and
Sales/Marketing (P(SM) = 41/584 = .070 = 7%).
By using the probability formula highlighted above, 3DR can show its attendees that the selected winners of the lottery were fair and that no bias was entered into the random selection process other than factual data collected via RFID wristbands.