Cumulative Cost .
Cumulative Cell Phone Cost (dollars)
600
(10, 504)
500+
(9,470)
400+
(8,418).
•(7, 361)
(6, 324)
300-
•(5,253)
200-
(3, 162) •(4,196)
100+(1,55)
(2, 108)
2
10
Number of Months
A line of best fit for this data is C = 51m + 4.4, where is the cumulative cell phone cost and m is the number of months.
Using this data, which value is the best prediction of the cumulative cell phone cost after 18 months?