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a) In Roosevelt National Forest, the rangers took random samples of live aspen trees and measured...

a) In Roosevelt National Forest, the rangers took random samples of live aspen trees and measured the base circumference of each tree. A sample of 116 trees had a mean circumference of 15.71 inches and a sample standard deviation of 4.63 inches. Find a 95% confidence interval for the mean circumference of all aspen trees in Roosevelt National Forest from this data.

b) Suppose a confidence interval constructed from this data was (14.945, 16,475) inches. What confidence level was used to produce this interval?

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