Concept explainers
A marathon is a fool race with a distance of 26.22 miles. It was one of the original events of the modem Olympics, where it was a men’s only
Training for a marathon typically lasts at least 6 months. The training is gradual, with increases in distance about every 2 weeks. About 1 to 3 weeks before the race, the distance run is decreased slightly. The stem-and-leaf plots below show the marathon training times (in minutes) for a random sample of 30 male runners and 30 female runners.
5. Use the sample to construct a 95% confidence interval for the population mean training time of all runners. How do your results differ from those in Exercise 3? Explain.
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Elementary Statistics: Picturing the World (7th Edition)
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