Determine and Interpret z-Scores
-A pharmaceutical testing company wants to test a new cholesterol drug. The average cholesterol of the target population is 200 mg and they have a standard deviation of 25 mg. The company wished to test a sample of people who fall between 1.5 and 3 z-scores above the mean. Into what range must a candidate s cholesterol level be in order for the candidate to be included in the study
A) $237.5 - 275$
B) $225 - 237.5$
C) $125 - 162.5$
D) $162.5 - 275$

Question

Determine and Interpret z-Scores
-A pharmaceutical testing company wants to test a new cholesterol drug. The average cholesterol of the target population is 200 mg and they have a standard deviation of 25 mg. The company wished to test a sample of people who fall between 1.5 and 3 z-scores above the mean. Into what range must a candidate s cholesterol level be in order for the candidate to be included in the study 
A) $237.5 - 275$
B) $225 - 237.5$
C) $125 - 162.5$
D) $162.5 - 275$

Quizplus · Accepted Answer

The z-score formula is $Z = \frac{(X - \mu)}{\sigma}$, where $X$ is the value, $\mu$ is the mean, and $\sigma$ is the standard deviation. For 1.5 z-scores above the mean, $X = 1.5 \times 25 + 200 = 237.5$. For 3 z-scores above the mean, $X = 3 \times 25 + 200 = 275$. Therefore, the range is $237.5 - 275$.

Determine and Interpret Z-Scores -A Pharmaceutical Testing Company Wants to Test

Determine and Interpret Z-Scores
-A Pharmaceutical Testing Company Wants to Test