IQ test scores are normally distributed with a mean of 104 and a standard deviation of 15. An individualʹs IQ score is found to be 111. Find the z-score corresponding to this value.
A)0.47
B)-0.47
C)2.14
D)-2.14

Question

Quizplus · Accepted Answer

The z-score is calculated using the formula $z = \frac{(X - \mu)}{\sigma}$, where $X$ is the value in question, $\mu$ is the mean, and $\sigma$ is the standard deviation. Substituting the given values, $z = \frac{(111 - 104)}{15} = \frac{7}{15} = 0.47$.

IQ Test Scores Are Normally Distributed with a Mean of 104