Gina wilson all things algebra I unit 4 test

Question 5 of 10 2 points if a population is a sample of the population could be a. registered voters; all citizens o o b. baptists; all religious people o c. people who purchased shoes; all customers o d. the entire school faculty; math teachers

How can you find the mean absolute deviation (mad) for this set of data?

Math i have no idea how to do a and b