C.5. At two years of age, sardines inhabiting Japanese waters have a length distribution that is approximately normal with mean 20.20cm and standard deviation 0.65cm. How long are the longest 15% of all these sardines?
Q. C.5. At two years of age, sardines inhabiting Japanese waters have a length distribution that is approximately normal with mean 20.20cm and standard deviation 0.65cm. How long are the longest 15% of all these sardines?
Identify z-score for 85th percentile: Identify the z-score that corresponds to the longest 15% of the distribution.We need to find the z-score for the 85th percentile since the longest 15% is the top 85%.Using a z-table or calculator, the z-score for the 85th percentile is approximately 1.04.
Use z-score formula: Use the z-score formula to find the length.The formula is: X=μ+(z×σ), where X is the length we want to find, μ is the mean, z is the z-score, and σ is the standard deviation.X=20.20+(1.04×0.65)
Calculate the length: Calculate the length.X=20.20+(1.04×0.65)X=20.20+0.676X=20.876cm
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