In a World Atlas study, 10% of people have blue eye color. Lane decided to observe 35 people and she concluded 6 people had blue eyes. Calculate the z-score.
A) 0.1714
B) 0.0710
C) 1.4086
D) 0.5675

Question

Quizplus · Accepted Answer

The z-score is calculated using the formula $z = \frac{(X - \mu)}{\sigma}$, where $X$ is the observed value, $\mu$ is the mean, and $\sigma$ is the standard deviation. For this problem, $X = 6$, $\mu = 35 \times 0.10 = 3.5$, and $\sigma = \sqrt{35 \times 0.10 \times (1 - 0.10)} = \sqrt{3.15} \approx 1.7748$. Thus, $z = \frac{(6 - 3.5)}{1.7748} \approx 1.4086$.

In a World Atlas Study, 10% of People Have Blue