Accu-Rating has just released its webcast report for last month. The report details the aggregate tuning hours for each of the top15

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 followinghistogram:

8

6

4

2

0

Frequency

3

2

2

7

1

20040060080010001200

Aggregate tuning hours (in thousands of hours)

Based on the histogram, estimate themeanaggregate tuning hours (in thousands of hours) for these radio stations. Carry your intermediate computations to at least four decimal places, androundyour answer to at least one decimal place.