tlglugglgutpihuc tlglugglgutpihuc 24-01-2017 Mathematics contestada the ages of people signed up for piano lessons are listed.11, 16, 15, 9, 19, 12, 13, 13, 11, 11, 18, 17what is the mode of the ages.a ( 13b ( 12c ( 15d ( 11