Question

Calculate the standard deviation by direct method-

2,8,10,7,8,5

Answer 1

Explanation:

Another convenient way of finding standard deviation is to use the following formula.

Standard deviation (by mean method) σ =

If di = xi – are the deviations, then

Example 8.5 The amount of rainfall in a particular season for 6 days are given as 17.8 cm, 19.2 cm, 16.3 cm, 12.5 cm, 12.8 cm and 11.4 cm. Find its standard deviation.

Solution Arranging the numbers in ascending order we get, 11.4, 12.5, 12.8, 16.3, 17.8, 19.2.

Number of observations n = 6