$15 per hour
Explanation:
The first coordinate that we are given is that for 2 hours, it costs $80, which can be represented as (2, $80).
The second coordinate that we are given is that for 4 hours, it costs $110, which can be represented as (4, $110).
The formula to find the slope with two given coordinates is: y2-y1/x2-x1
Plug in (substitute) the corresponding numbers into its appropriate places and evaluate .
110-80/4-2 = 30/2 = 15
$15 per hour
