Question

Consider a distribution with a mean of 15 and a standard deviation of 3.

If an observation from the distribution has a z-score of -2, what is the value?

Consider a distribution with a mean of 15 and a standard deviation of 3. If an observation from the distribution has a z-score of -2, what is the value?

Answer 1

Solution :

Given that,  

mean = $\mu$ = 15

standard deviation = $\sigma$ = 3

Using standard normal table ,

z = -2

Using z-score formula,

x = z * $\sigma$ + $\mu$

x = -2 * 3 + 15 = 9

Value = 9