for a standard normal distribution, which of the following variables always equals 0?\no μ\no σ\no x\no z

Explanation:

Step1: Recall properties of standard normal

A standard - normal distribution has mean $\mu = 0$ and standard deviation $\sigma=1$.

Step2: Analyze each variable

• $\mu$ represents the mean of the distribution. For a standard normal, $\mu = 0$.
• $\sigma$ represents the standard deviation. For a standard normal, $\sigma = 1$.
• $x$ is a general value from the normal distribution and can take on any real - valued number.
• $z$ is the standardized value calculated as $z=\frac{x - \mu}{\sigma}$, and it can take on any real - valued number.

Answer:

$\mu$