Serum Cholesterol Levels. According to the National Health and Nutrition Survey,

Question

Serum Cholesterol Levels. According to the National Health and Nutrition Survey, the serum (noncellular portion of the blood) total cholesterol levels of U.S. females 20 years old or older is normally distributed with a mean of 206 mg/dL and a standard deviation of 44.7 mg/dL. Let x denote serum total cholesterol level for U.S. females 20 years old or older. a) The percentage of U.S. females 20 years old or older who have a serum total cholesterol level between 150 mg/dL and 250 mg/dL is equal to the area under the standard normal curve between _____ and _____.

b) The percentage of U.S. females 20 years old or older who have a serum total cholesterol level below 220 mg/dL is equal to the area under the standard normal curve that lies to the _____ of _____.

Explanation / Answer

a)

Z=(150-206)/44.7 =-1.25

Z=(250-206)/44.7=0.98

So answer is the standard normal curve between _____-1.25___________ and _____0.98______

b)

Z=(220-206)/44.7 =0.31

The percentage is

P(Z<0.31) =0.6217

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.