Respuesta :
Answer:
$ 8535
Step-by-step explanation:
Given,
The average cell phone bill in 2009 = $ 650,
Since, the average cost each year is about 109.2% of the previous year,
Thus, there is a GP, that shows the average cell phone bill of every year,
That having first term, a = 650,
Common difference, d = 109.2 % = 1.092,
Thus, the total cell phone bill for 2009-2018 = Sum of the 9 terms of the above G.P.
[tex]S_{n}=\frac{a(r^n-1)}{r-1}[/tex]
[tex]S_{9}=\frac{650(1.092^9-1)}{1.092-1}[/tex]
[tex]=8534.95058244[/tex]
[tex]\approx 8535[/tex]
Hence, The person will pay approximately $ 8535 for 2009 - 2018.
First option is correct.