Question

a normal distribution of data has a mean of 15 and a standard deviation of 4. how many standard deviations from the mean is 25?
0.16
0.4
2.5
6.25

Explanation:

Step1: Recall z - score formula

The z - score formula is $z=\frac{x-\mu}{\sigma}$, where $x$ is the data - point, $\mu$ is the mean, and $\sigma$ is the standard deviation. The z - score represents the number of standard deviations a data - point is from the mean.

Step2: Identify values

We are given that $\mu = 15$, $\sigma=4$, and $x = 25$.

Step3: Substitute values into formula

$z=\frac{25 - 15}{4}=\frac{10}{4}=2.5$

Answer:

C. 2.5