What is the standard deviation of these four scores: 2, 4, 3, 7?
A)1.87
B)2.35
C)3.50
D)4.05

Question

Quizplus · Accepted Answer

The standard deviation is calculated by finding the square root of the average of the squared deviations from the mean. First, find the mean: (2+4+3+7)/4 = 4. Then, find each score's deviation from the mean, square those deviations, and average them: [(2-4)^2 + (4-4)^2 + (3-4)^2 + (7-4)^2]/4 = [4 + 0 + 1 + 9]/4 = 14/4 = 3.5. Finally, take the square root of 3.5, which is approximately 1.87.

What Is the Standard Deviation of These Four Scores: 2