Question

while observing the fare meter in a taxi, a student records the following data: reading on taxi fare meter time (minutes) meter reading 0 $5.25 10 $13.75 20 $22.25 30 $30.75 what is the equation that relates the cost, c(t), of the taxi ride and time, t, in minutes? what is the cost of a 12-minute taxi ride?

Answer 1

(0,5.25)(10,13.75)
slope(m) = (y2 - y1) / (x2 - x1)
slope(m) = (13.75 - 5.25) / (10 - 0) = 8.5/10 = 0.85

y = mx + b
(0,5.25)...x = 0 and y = 5.25
slope(m) = 0.85
now we sub, we r looking for b, the y int
5.25 = 0.85(0) + b
5.25 = b

so ur equation is : y = 0.85x + 5.25 or C(t) = 0.85t + 5.25 <==

cost of a 12 min taxi ride.....sub in 12 for t
C(t) = 0.85t + 5.25
C(12) = 0.85(12) +5.25
C(12) = 10.20 + 5.25 = 15.45 
so a 12 min ride would cost u : $ 15.45 <==