# What is the z-score of sample X, if n = 121, mu= 33, St. Dev. =110, and E[X] =46?

Nov 11, 2016

The z-score is $= 1.3$

#### Explanation:

The z-score for a sample mean is $= \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

Therefore, the z-score is $\frac{46 - 33}{\frac{110}{\sqrt{121}}} = \frac{13}{\frac{110}{11}} = \frac{13}{10} = 1.3$