Question

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 a number of hours parked, what is the cost to park for 3 hours?

Answer 1

I think it would be $3.50.

Answer 2

If the charge is a linear function, we need to find the slope of the line. In this problem, money charged is a function of hours parked... f(h) = $ Your points then are (hours, dollars) We have two points... (4, 5.5), (7, 7.75) The slope is the rise over the run... m = (7.75 - 5.5)/(7-4) = 2.25/3 = .75 If the hours decrease by 1, the charge will decrease by $.75. At 4 hours we charge, $5.50 For 3 hours we charge $5.50 - $.75 = $4.75