Answer:
statistical parameter
Explanation:
In this scenario, Brian Vanecek is using a statistical parameter also known as a population parameter. This is the best explanation to what Brian is using since he is calculating the average waiting time based on the information gathered from a randomly selected sample of the population. Since this sample was random it exemplifies the entire population and therefore allows for the data to be generalized to that population. Using the statistics gathered he can calculate the average waiting time as a statistical parameter of the population.