The number of online buyers in Western Europe grew steadily over the past decade. The function P(t) = 27.1 + 14.79 Int (1 st7) gives the number of online buyers as a percent of the total population, where t is measured in years, with t = 1 corresponding to 2001. (a) What was the percentage of online buyers in 2004? (Round your answer to two decimal places.) ---Select-- (b) How fast was it changing in 2004? (Round your answer to two decimal places.) --Select--