Question

What is the standard deviation of the following data set rounded to the nearest tenth? 56,78,123,34,67,91,20

Answer 1

32.2

Explanation:

The given data set is:

56,78,123,34,67,91,20

The mean of this data set is

`(56+78+123+34+67+91+20)/(7) =(469)/(7) =67`

The standard deviation is given by;

`SD=\sqrt{(\sum(x-\bar X)^2)/(n) }`

`SD=\sqrt{((56-67)^2+(78-67)^2+(123-67)^2+(34-67)^2+(67-67)^2+(91-67)^2+(20-67)^2)/(7) }`

`SD=\sqrt{(7252)/(7) }`

`SD=√(1036)=32.2`