An electric power plant uses solid waste for fuel in the production of electricity. The cost Y in dollars per hour to produce electricity is Y=9+0.3X+0.27X², where X is in megawatts. Revenue in dollars per hour from the sale of electricity is 13X-0.2X2. Find the value of X that gives maximum profit. The value of X that gives maximum profit is megawatts. (Round to two decimal places.)