In July 2005, the internet was linked by a global network of about 352.7 million host computers. The number of host computers has been growing approximately exponentially and was about 35.5 million in July 1998.

(a) Find a formula for the number, N, of internet host computers (in millions of computers) as an exponential function of t, the number of years since July 1998, using the continuous exponential model $N(t) = ae^{kt}$. What are the values of a and k in your model?
$a =$ help (numbers)
$k =$ (Accurate to four decimal places)

(b) Based on your equation above, what is the continuous annual percentage growth rate of N? Round your answer to the nearest 0.01%.
By %

(c) What is the doubling time of N? years (round your answer to the nearest 0.001 years)