On a standardized exam, the scores are normally distributed with a mean of 80 and a standard deviation of 25. Find the z-score of a person who scored 90 on the exam.
To find the z-score of a person who scored 90 on the exam, we can use the formula:
\[ z = \frac{x - \mu}{\sigma} \]
Where:
- x = score of the person (90)
- μ = mean of the distribution (80)
- σ = standard deviation of the distribution (25)
Plugging in the values:
\[ z = \frac{90 - 80}{25} = \frac{10}{25} = 0.4 \]
Therefore, the z-score of a person who scored 90 on the exam is 0.4.