Sum of Square


Statistics – Sum of Square


”;


In statistical data analysis the total sum of squares (TSS or SST) is a quantity that appears as part of a standard way of presenting results of such analyses. It is defined as being the sum, over all observations, of the squared differences of each observation from the overall mean.

Total Sum of Squares is defined and given by the following function:

Formula

${Sum of Squares = sum(x_i – bar x)^2 }$

Where −

  • ${x_i}$ = frequency.

  • ${bar x}$ = mean.

Example

Problem Statement:

Calculate the sum of square of 9 children whose heights are 100,100,102,98,77,99,70,105,98 and whose means is 94.3.

Solution:

Given mean = 94.3. To find Sum of Squares:

Calculation of Sum of Squares.
Column A
Value or Score
${x_i}$
Column B
Deviation Score
${sum(x_i – bar x)}$
Column C
${(Deviation Score)^2}$
${sum(x_i – bar x)^2}$
100 100-94.3 = 5.7 (5.7)2 = 32.49
100 100-94.3 = 5.7 (5.7)2 = 32.49
102 102-94.3 = 7.7 (7.7)2 = 59.29
98 98-94.3 = 3.7 (3.7)2 = 13.69
77 77-94.3 = -17.3 (-17.3)2 = 299.29
99 99-94.3 = 4.7 (4.7)2 = 22.09
70 70-94.3 = -24.3 (-24.3)2 = 590.49
105 105-94.3 = 10.7 (10.7)2 = 114.49
98 98-94.3 = 3.7 (3.7)2 = 3.69
${sum x_i = 849}$ ${sum(x_i – bar x)}$ ${sum(x_i – bar x)^2}$
  First Moment Sum of Squares

Advertisements

”;

Leave a Reply

Your email address will not be published. Required fields are marked *