Find the standard deviation for the following data set:
2, 2, 2, 5, 5, 6, 6, 8, 8, 9
A) 2
B) 6.21
C) 2.49
D) 5

Question

Quizplus · Accepted Answer

The standard deviation is calculated by finding the square root of the variance. First, find the mean (average) of the data set: (2+2+2+5+5+6+6+8+8+9)/10 = 5.3. Then, find the variance by averaging the squared differences from the Mean: [(2-5.3)^2 + (2-5.3)^2 + (2-5.3)^2 + (5-5.3)^2 + (5-5.3)^2 + (6-5.3)^2 + (6-5.3)^2 + (8-5.3)^2 + (8-5.3)^2 + (9-5.3)^2] / 10 = 6.21. Finally, take the square root of the variance to get the standard deviation: √6.21 ≈ 2.49.

Find the Standard Deviation for the Following Data Set