The average annual salary of the employees of a company in the year 2005 was $70,000. It increased by the same factor each year and in 2006, the average annual salary was $82,000. Let f(x) represent the average annual salary, in thousand dollars, after x years since 2005. Which of the following best represents the relationship between x and f(x)?

f(x) = 70(1.17)x
f(x) = 82(1.17)x
f(x) = 70(2.2)x
f(x) = 82(2.2)x

Question

The average annual salary of the employees of a company in the year 2005 was $70,000. It increased by the same factor each year and in 2006, the average annual salary was $82,000. Let f(x) represent the average annual salary, in thousand dollars, after x years since 2005. Which of the following best represents the relationship between x and f(x)?

f(x) = 70(1.17)x 
f(x) = 82(1.17)x 
f(x) = 70(2.2)x 
f(x) = 82(2.2)x