A small lake is stocked with a certain species of fish. The fish population is modeled by the function P = 10 1 + 4e −0.8t where P is the number of fish in thousands and t is measured in years since...

(a) Find the fish population after 4 years. (Round your answer to the nearest whole fish.)
  fish


(b) After how many years will the fish population reach 5000 fish? (Round your answer to two decimal places.)