Suppose that a travel bureau claims that the trees in a forest or 84 feet tall on average, with a standard deviation of 0.2 feet. if you took a sample of 64 trees, which of the following mean heights would be outside the 95% confidence interval?

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graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.