A sample of n = 9 scores is randomly selected from a population with µ = 80 and ? = 9.If the sample mean is M = 83,then the corresponding z-score is z = +3.00.

Question

Quizplus · Accepted Answer

The z-score is calculated using the formula $z = \frac{M - \mu}{\sigma / \sqrt{n}}$, where $M$ 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: $z = \frac{83 - 80}{9 / \sqrt{9}} = \frac{3}{3} = 1$. Thus, the correct z-score is $z = +1.00$, not $z = +3.00$.

A Sample of N = 9 Scores Is Randomly Selected