The following data represents the body mass index in a random group of twelve
diabetic patients in a clinic.
18, 28, 31, 14, 25, 21, 22, 28, 35, 29, 27, 22.
What is the z score of the person with the lowest and highest body mass index?
Z = (score-mean)/SD
Find the mean first = sum of scores/number of scores
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation = square root of variance
I'll let you do the calculations.