Joan was severely injured when she ingested medication that was improperly labeled in violation of the Federal Drug Act. Joan retained an attorney to assist her with a potential claim against Pharmaceutical Company. After some initial investigation, Attorney determined there were hundreds of other persons who were injured due to mislabeling of the same medication Joan had ingested. Attorney decided to file a class action lawsuit against Pharmaceutical Company. The prerequisites for filing a class action lawsuit in Federal Court, according to the Federal Rules of Civil Procedure are