Question

The z-score for a normal distribution is the number of standard deviations from the mean. If our data values are denoted by X, for example, and if the mean is 10 and the standard deviation is 3, then if X is 4.5 the z-score for this value is

Answer 1

Given:

Mean = 10

standard deviation = 3

X = 4.5.

The formula for z-score is,

$\begin{gathered} z=\frac{X-\mu}{\sigma} \\ z=\frac{4.5-10}{3} \\ z=-\frac{11}{6} \\ z=-1.83 \end{gathered}$

Answer: z-score is -1.83.