Question

Since the beginning of satellite radio in 2001, the number of satellite radio subscribers has been growing very quickly. At the end of 2001, the total number of subscribers to XM Satellite radio was 27,733. By the end of 2005, the number of subscribers had grown to 5,932,957. Find an exponential function with f(x) =f0a^x−2001 that models the number of XM subscribers, where x is the year and f (x) gives the number of subscribers in millions.

Answer 1

5932957 = 27733(a)^4

213.9313 = a^4
take 4th root of both sides
a = 3.824446

so f(x) = 27733(3.824446)^(x-2001)