Three dentists wanted to compare the ages of their patients. they each calculated their patients’ mean age and the mean absolute deviation of their ages. they displayed the results in a table. which statements are true? choose exactly two answers that are correct. dentist mean patient age mad appiah 43 9.7 cantwell 29 13.9 singh 41 14.1 a. dr. appiah’s patients’ ages vary more than do dr. cantwell’s patients’ ages. b. dr. appiah’s patients’ ages vary less than do dr. singh’s patients’ ages. c. dr. cantwell’s patients’ ages and dr. singh’s patients’ ages vary about the same amount. d. dr. singh’s patients’ ages and dr. appiah’s patients’ ages vary about the same amount.

Design an er diagram for keeping track of information about votes taken in the u. s. house of representatives during the current two-year congressional session. the database needs to keep track of each u. s. state's name (e. g., texas', new york', california') and include the region of the state (whose domain is {northeast', midwest', southeast', southwest', west'}). each congress person in the house of representatives is described by his or her name, plus the district represented, the start date when the congressperson was first elected, and the political party to which he or she belongs (whose domain is {republican', democrat', 'independent', other'}). the database keeps track of each bill (i. e., proposed law), including the bill name, the date of vote on the bill, whether the bill passed or failed (whose domain is {yes', no'}), and the sponsor (the congressperson(s) who sponsored - that is, proposed - the bill). the database also keeps track of how each congressperson voted on each bill (domain of vote attribute is {yes', no', abstain', absent'}). additional information: