(1) As can be seen from Figure ①, the percentage of daily working hours of residents in our city is1-7.4%-46.5%-14.5% = 31.6%;

(2) If the one-time use time is 24×60× 14.5%=208.8 minutes, the daily online time is 208.8× 12%=25.06 minutes;

(3) It is good for your health to spend less time watching TV and do more exercise.