Question

To compute either the variance or standard deviation, you first must find the sum of the squared deviation scores – also called the sum of squares or simply SS. For the following set of scores: 5, 2, 8, 3

a. Compute SS with the computational formula. (Be sure to write out the formula &

b. Compute SS with the definitional formula. show your work for a & b)

c. Which formula is better suited for these data? Why?

d. Does the value you obtain for SS depend on whether these scores are a sample or a population?

Answer 1

c) The computational formula is better suited because it requires less calculation whereas in definition formula needs larger computation time

NOTE: Any calculator also uses a computational formula to calculate the sum of squares

d)No SS doesn't depend upon whether the data is from sample or population

NOTE: variance depends upon whether the data is from sample or population.

if data is from sample , variance = SS/(n-1)

If data is from population variance = SS / n