Use the Chebyshev interval to determine

A marine biologist wants to know the body sizes of an endangered species of dolphin. Neither the population mean nor the population standard deviation is known for this species. The biologist knows that the species has failed to reproduce in the past ten years, and so she assumes that the size distribution is negatively skewed, with more larger adults than would be the case if the distribution were normal. She is only able to measure 10 animals, finding a mean length x bar = 2.667 meters with a standard deviation of 0.820 meters. Use the Chebyshev interval to determine the at-Ieast-95% approximate confidence interval for the population mean..