-Is variance affected by N? why or why not?
-what does variation summarize?
-why is it not a good descriptive statistic?
the average squared deviation or “mean squared deviation”: σ²= ss/N
-Variance is not affected by N, because it is an average of squared deviations
-Variance summarizes the amount of deviation, allows for comparisons between different-sized groups, & is useful for further analyses.
-Since variance is a mean of squared deviations, it is not on the same scale as our original variable SO not a good descriptive statistic.