Question

In a certain normal distribution of scores, the mean is 30 and the standard deviation is 3. Find the z-score corresponding to a score of 23. a. 10.00 c. 7.7 b. 2.33 d. –2.33 Please select the best answer from the choices provided A B C D

Answer 1

Answer:

d. –2.33

Step-by-step explanation:

The z-score can be calcualted with the following formula

$Z=\frac{x-\mu}{\sigma}$

Where $\mu$ is the mean and $\sigma$ is the standard deviation.

So, in this problem, we have the following data

$x=23\\\mu =30\\\sigma=3$

Replacing all values in the formula, we have

$Z=\frac{23-30}{3}=\frac{-7}{3} \approx -2.33$

Therefore, the right answer is d.