In 1986 there were 339720 cell phone subscribers in the Unit

In 1986, there were 339,720 cell phone subscribers in the United States. By 2008, the number of cell phone subscribers increased to 262,665,000. What is the geometric mean annual increase for the period?(Round your answer to 2 decimal places.) PLEASE HELP.

GEOMETRIC MEAN %______

Solution

If r = the geometric mean increase,

262665000 = 339720(1+r)^(2008-1986)

262665000 = 339720(1+r)^22

(1+r)^22 = 773.1808548

1 + r = 1.352961705

r = 0.352961705 or 35.2961705% OR 35.30% [ANSWER]