A model for the number of bacteria in a culture after t hours is given by

P(t) = P₀e^kt, k > 0.

(a) Find the growth constant k if it is known that after 1 hour the colony has expanded to 1.2 times its initial population. (Round your answer to four decimal places.)

k = _________

(b) Find the time that it takes for the culture to quadruple in size. (Round your answer to two decimal places.) t = ______ hr