Answer:
A. 1
B. -1
C. -1.67
D. 0.67
E. 3.33
Explanation:
Mathematically;
z-score = (x-mean)/SD
From the question, mean = 20 , SD = 3 while x represents the individual values
A. 23
Z = (23-20)/3 = 3/3 = 1
B. 17
z = (17-20)/3 = -3/3 = -1
C. 15
z = (15-20)/3 = -5/3 = -1.67
D. 22
z = (22-20)/3 = 2/3 = 0.67
E. 30
z = (30-20)/3 = 10/3 = 3.33