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Violet wants to make sure she receives a B- in Art on her report card, in order to get a B-, she needs to have a mean of 80. What grade does she need to get on her last project in order to get a mean of 80?
Here are the scores she has received so far: 70, 83, 83, 71, 83, 80, 82, 81, 78
Violet needs to get an 89 on her final project to bring her mean up to 80