Question

the denominator of the z for an individual score formula is: sd; σ or sd; if you do not know σ you can use sd; σ. question 4 0.66 pts if a given z - score is negative, then the raw score is is representing was: above the population mean; below the population mean; at the population mean

Explanation:

Step1: Recall z - score formula

The formula for the z - score of an individual score is $z=\frac{x-\mu}{\sigma}$ (population standard - deviation known) or $z = \frac{x-\mu}{SD}$ (sample standard - deviation used when population standard - deviation $\sigma$ is unknown). The denominator is either $\sigma$ or $SD$.

Step2: Recall the meaning of z - score

The z - score formula is $z=\frac{x - \mu}{\sigma}$ (or $SD$). If $z\lt0$, then $x-\mu\lt0$ (since $\sigma\gt0$ or $SD\gt0$), which implies $x\lt\mu$. Here, $x$ is the raw score and $\mu$ is the population mean.

Answer:

Question 1: B. $\sigma$ or $SD$; if you do not know $\sigma$ you can use $SD$
Question 2: B. below the population mean