In July 2005, the internet was linked by a global network of about 352.8 million host computers. The number of host computers has been growing approximately exponentially and was about 36.9 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 exponential function of the form N(t)=aekt. What are the values of a and k in your model? a= k = help (numbers) (Either enter the answer in exact form, or a numerical approximation accurate to four decimal places.) (b) Based on your equation above, what is the annual percentage growth rate of N? (Enter your answer in exact form, or a numerical approximation that is accurate to 0.01 %. Do not use approximations before the final answer.) By (c) What is the doubling time of N? % years (round your answer to the nearest 0.001 years)