Too much cholesterol in the blood increases the risk of heart disease. The cholesterol levels of young women age 20 to 34 have an approximate Normal distribution with mean 185 milligrams per deciliter (mg/dL) and standard deviation 39mg/dL.About what percent of young women in this age group will have cholesterol levels less than 150mg/dL ?82%90%18%
Q. Too much cholesterol in the blood increases the risk of heart disease. The cholesterol levels of young women age 20 to 34 have an approximate Normal distribution with mean 185 milligrams per deciliter (mg/dL) and standard deviation 39mg/dL.About what percent of young women in this age group will have cholesterol levels less than 150mg/dL ?82%90%18%
Identify parameters: Identify the parameters of the normal distribution.Mean μ = 185 mg/dLStandard Deviation σ = 39 mg/dLWe need to find the probability that cholesterol levels are less than 150 mg/dL.
Calculate Z-score: Calculate the Z-score for 150mg/dL. Z=σX−μZ=39150−185Z=39−35Z≈−0.897
Use Z-score: Use the Z-score to find the corresponding percentile from the standard normal distribution table. Looking up Z=−0.897, we find that the percentile is approximately 18%.
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