Consider the following small set of scores. Each number represents the number of siblings reported by each of the N = 6 persons in the sample:

X scores are: [0 1 1 1 2 7]

a. Compute the mean (M) for this set of six scores.
b. Compute the six deviations from the mean (X – M) and list these six deviations.
c. What is the sum of the six deviations from the mean you reported in 1b? Is this outcome a surprise?
d. Now calculate the sum of squared deviations (SS) for this set of six scores.
e. Compute the sample variance, s2, for this set of six scores.
f. When you compute s2, why should you divide SS by (N-1) rather than N?
g. Finally, compute the sample standard deviation (denoted either by s or SD).