Alejandro has just gotten a new job. The relationship between the number of hours he works, xx, and his total earnings, yy, is represented by the graph below. A point (4,904,90) is labeled below. Which statement about the graph is true?
0
Number of Hours
Total Earning (in dollars)
x
y
0
Number of Hours
Total Earning (in dollars)
(4 , 90)

The unit rate is 4 hours per dollar
The unit rate is 22.5 hours per dollar
The unit rate is $90.00 per hour
The unit rate is $22.50 per hour