The average time it takes a person in a one-person canoe to complete a certain river course is 47 minutes. Because of rapid currents in the spring, a group of 10 people traverse the course in an average of 42 minutes. The standard deviation, known from previous trips, is 7 minutes. Test the claim that this group’s time was different because of the strong currents. Use α = 0.10. Find the 90% confidence interval of the true mean. Does the confidence interval interpretation agree with the results of the hypothesis test? Explain. Assume that the variable is normally distributed.
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