Question

A cell phone carrier charges a fixed monthly fee plus a constant rate for each minute used. Part 1. In January, the total cost for 150 minutes was $ 62 while in February, the total cost for 175 minutes was $ 64 . The constant charge for each minute used is:

a. 0.09

b. 0.1

c. 0.08

Part 2. The fixed montly fee charged by the carrier is;

fee = $__________________

Answer 1

9514 1404 393

Answer:

c. $0.08

fee = $50

Explanation:

We are given two ordered pairs:

(minutes, charges) = (150, 62) and (175, 64)

The slope of the graph of charges is ...

m = (y2 -y1)/(x2 -x1) = (64 -62)/(175 -150) = 2/25 = 0.08

The charge for each minute is $0.08.

__

The y-intercept of the graph can be found from ...

b = y -mx

b = 62 -150(0.08) = 62 -12 = 50

The fixed monthly fee is $50.