Test scores are normally distributed with a mean of 100 and a standard deviation of 15. An individual score is found to be 90. Find the Z-score corresponding to this value.
A. -0.67
B. 0.67
C.1.33
D.-1.33

Because the boundary value is less than the mean, you automatically know the z score will be negative.

z = (x - mu)/sigma = (90 - 100)/15 = -10/15 = -2/3 = -.67

Step-by-step explanation:

ruth is 6 years old

step-by-step explanation:

6 + 24 = 30,   so 6/30 = .2  

if you do 1/5 it also equals .2, so that is the answer.