How to find the mean and standard deviation?

Question

Country       Number of Television Sets Per 100 People

A                            126

B                             96

C                            131

D                            111

E                            116

 

Answer 1

The mean is just the average of the points.

 

(126 + 96 + 131 + 111 + 116) / 5

= 116

 

To find the stdev, you need to find the square root of the sum of the difference from each point from the mean squared.

 

σ = √[ ∑(x-mean)^2 / N ]

 

√[(126 - 116)^2 + (96 - 116)^2 + (131 - 116)^2 + (111 - 116)^2 + (116-116)^2) / 5]

√[750/5]

√[150]

12.25