PLEASE REALLY NEED HELP!!

A line on a graph shows a proportional relationship between the hours worked, x, and the total pay y. Two points on the graph are located at (6, 58.50) and (9, 87.75) .

What is the unit rate for the pay per hour?

$4.88 per hour

$9.75 per hour

$19.50 per hour

$29.25 per hour