Anita is training for a marathon and runs different distances each day. Over the first 5 days, she runs the following distances: 8 miles, 10 miles, 7 miles, 12 miles, and 9 miles. Her friend Bella runs 75% of the total distance that Anita runs over these 5 days. How many miles does Bella run on average each day? Let's think step by step and output the final answer within \boxed{}.
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