A parking garage charges $5.50 to park for 4 hours and $7.75 to park for 7 hours. If the cost is a linear function of the number of hours parked, what is the cost to park for 3 hours?
slope = (7.75 - 5.50)/(7 - 4) = 2.25/3 = 0.75 The equation described by the function is y - 5.5 = 0.75(x - 4) y = 0.75x - 3 + 5.5 = 0.75x + 2.5 For x = 3, y = 0.75(3) + 2.5 = 2.25 + 2.5 = 4.75 Therefore, it costs $4.75 to park for 3 hours.
