How do you calculate the standard deviation of 3.4, 6.1, 7.3, 4.5, 2.3, 4.4, 9.4, 3.4, 2.3, 7.2?

1 Answer
Aug 2, 2017

Standard deviation is #2.26(2dp)#

Explanation:

Data: #{3.4, 6.1, 7.3, 4.5, 2.3, 4.4, 9.4, 3.4, 2.3, 7.2} = 50.3#

Mean: #50.3/10=5.03#

Variance is average of the squared differences from the Mean.

Variance : #sigma^2 = 1/10* ((3.4-5.03)^2 + (6.1-5.03)^2 +(7.3-5.03)^2 #

#+ (4.5-5.03)^2+(2.3-5.03)^2+(4.4-5.03)^2+(9.4-5.03)^2 #

#+(3.4-5.03)^2+(2.3-5.03)^2+(7.2-5.03)^2) = 1/10 *51.001 = 5.1001 #

Standard Deviation is the square root of Variance,

Standard deviation : #sigma = sqrt(5.1001) = 2. 25834 ~~ 2.26(2dp)#