# What is the z-score of sample X, if #n = 36, mu= 12.3, St. Dev. =21, and mu_X =18.5#?

##### 1 Answer

May 8, 2016

#z=1.77#

#### Explanation:

#z=(mu-mu_x)/(SE)#

#SE=sigma/sqrt n=21/sqrt36=21/6=3.5#

#z=(12.3-18.5)/3.5=(-6.2)/3.5=-1.77#