Too much cholesterol in the blood increases the risk of heart disease. The cholesterol levels of young women aged 20 to 34 vary approximately Normally with mean 185 milligrams per deciliter (mg/dl) and standard deviation 39 mg/dl. Cholesterol levels for middle-aged men vary Normally with mean 222 mg/dl and standard deviation 37 mg/dl. Sandy is a young woman with a cholesterol level of 220. Her father has a cholesterol level of 250. Who has relatively higher cholesterol?

To solve this problem, simply obtain the z-score for Sandy's and her fathers' cholesterol levels within their respective distributions. The one with the highest z-score has the highest relative cholesterol.

Sandy:

X= 220 mg/dl

Mean (μ) = 185 mg/dl

Standard deviation (σ) = 39 mg/dl

[tex]z= \frac{X- \mu}{\sigma}=\frac{220 - 185}{39}\\ z=0.897[/tex]

Her Father:

X= 250 mg/dl

Mean (μ) = 222 mg/dl

Standard deviation (σ) = 37 mg/dl

[tex]z= \frac{X- \mu}{\sigma}=\frac{250 - 222}{37}\\ z=0.757[/tex]

Therefore, Sandy has a relatively higher cholesterol