Compute the Standard Deviation of a Variable from Raw Data
-149, 106, 114, 293, 106, 162, 224, 226, 230
A) 67.0
B) 63.2
C) 4487.9
D) 3989.2

Question

Quizplus · Accepted Answer

The standard deviation is calculated by first finding the mean of the data, then calculating the squared difference from the mean for each data point, summing those squared differences, dividing by the number of data points to find the variance, and finally taking the square root of the variance. For the given data: mean = (149 + 106 + 114 + 293 + 106 + 162 + 224 + 226 + 230) / 9 = 1670 / 9 ≈ 185.56. Then, calculate each data point's squared difference from the mean, sum those, divide by the number of data points, and take the square root. Doing this calculation gives a standard deviation of approximately 67.0.