The weekly hours worked by police officers in a small city are normally distributed with a mean of 45 hours and a standard deviation of 3 hours. ( = 45, = 3)

(i) Using the empirical rule, about 68% of police officers work between what two amounts of hours?

(ii) About 95% of police officers work between what two amounts of hours?

(iii) About 99.7% (almost all) of police officers in the city work between what two amounts of hours?