A set of normally distributed scores has a mean equal to 75 with a standard deviation equal to 25. If a score equals 100, then zobs for this score is.
A)+1.0
B)+2.0
C)+3.0
D)cannot determine without knowing sample size

Question

Quizplus · Accepted Answer

The z-score is calculated using the formula $z = \frac{(X - \mu)}{\sigma}$, where $X$ is the score, $\mu$ is the mean, and $\sigma$ is the standard deviation. Plugging in the given values, $z = \frac{(100 - 75)}{25} = 1$, so the correct answer is +1.0.

A Set of Normally Distributed Scores Has a Mean Equal