Accu-Rating has just released its webcast report for last month. The report details the aggregate tuning hours for each of the top 15 radio stations broadcast over the web. (The aggregate tuning hours for a station is the sum total of all hours that listeners tuned to the station.) The report displays the following histogram: Frequency 7 2 2 2 2 200 400 600 800 1000 1200 Aggregate tuning hours (in thousands of hours) Based on the histogram, estimate the mean aggregate tuning hours (in thousands of hours) for these radio stations. Carry your intermediate computations to at least four decimal places, and round your answer to at least one decimal place