Use the following information for questions:
Assume the cholesterol level in a certain population has mean $\mu$ = 200 and standard deviation $\sigma$ = 24. The cholesterol levels for a random sample of n = 9 individuals are measured and the sample mean $\overline{x}$ is determined.
-What is the z-score for a sample mean $\overline{x}$ = 180?
A) -3.75
B) -2.50
C) -0.83
D) 2.50

Question

Use the following information for questions:
 Assume the cholesterol level in a certain population has mean $\mu$ = 200 and standard deviation $\sigma$ = 24. The cholesterol levels for a random sample of n = 9 individuals are measured and the sample mean $\overline{x}$ is determined.
-What is the z-score for a sample mean $\overline{x}$ = 180?
A) -3.75
B) -2.50
C) -0.83
D) 2.50

Quizplus · Accepted Answer

The z-score for a sample mean is calculated using the formula $z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$, where $\overline{x}$ is the sample mean, $\mu$ is the population mean, $\sigma$ is the population standard deviation, and $n$ is the sample size. Plugging in the given values: $z = \frac{180 - 200}{\frac{24}{\sqrt{9}}} = \frac{-20}{8} = -2.5$.

Use the Following Information for Questions: Assume the Cholesterol μ\muμ

Use the Following Information for Questions:
Assume the Cholesterol $\mu$