What is meant by demography

Doctors recommend that both men and women take an aspirin every day to prevent heart attacks. however, the sample in the research study only contained men. the problem with doctors making this aspirin recommendation reflects a bias.

Cindy is 18 years old. cindy's parents and her 23-year old brother rich are going away for the weekend. renee, cindy's best friend, is pressuring her to throw a huge saturday night party for all their friends since no one will be home. renee even asked rich if he could pick up a few kegs for them. rich brought back two kegs of beer, a bottle of vodka, and a few bottles of wine, which he hid in the basement. renee also spread the word around school for everyone to show up. cindy now has over $100 worth of alcohol hid in the basement, an empty house for the weekend, and several friends expected to show. what should she do?

What was the social class pyramid during the civil war?