Due to the increase in hourly wages that each employee receives each year increases every three years by $ 0.50, this means that the increase remains constant over a period of 3 years, therefore the function described by this scenario is:
y= {0.5 if x <3
{1 if 3 ≤ x <6
{1.5 if 6 ≤ x <9
{2 if 9 ≤ x <12
Therefore, the last graph correctly represents the salary increase for x <12.
