From 2003 onward, the number of daily visitors to a website increased by 200% every two years. So, for example, the number of visitors in 2011 was 200% more than the number of visitors in 2009. In what year was the number of daily visitors 800% more than the number of daily visitors in 2003?
If the number of visitors was, say, 100 people in 2003, then in 2005 that number would have gone up to 300 people, which is 200% increase. And that number would have gone up to 900 people in 2007, which is 800% increase.
So, it takes 4 years for daily visitors to grow by 800%.
Another way of looking at it is to find ANNUAL percentage increase as follows:
300 people / 100 people =3-folds increase in 2 years. So the yearly increase would be:
3^1/2 =1.73205 - 1 x 100 = 73.205% average compound annual increase.
900 people =100 x [1 + 73.205%]^N divide both sides by 100
9 = 1.73205^N take the log of both sides.
N =Log(9) / Log(1.73205)
N = 4 Years for the number of visitors to grow by 800%.
