Given examples of two or more distributions in the form of a graph, state which is the most or least variable.
Given two or more sets of scores, state which is the most or least variable.
Define and be able to calculate the range.
Define the interquartile and semi-interquartile range; Given Q1 (X25) and Q3 (X75), calculate the interquartile range and semi-interquartile range.
Define the sum of squares, variance, and standard deviation, and explain the relationship among them.
Recognize that the sum of squares, variance, and standard deviation, all measure variability.
Given a set of scores that all have the same value, state what the sum of squares, variance, and standard deviation would be.
Calculate the sum of squares, variance, and standard deviation, using either the deviation formula or the computational (raw score) formula.
Know the perfect squares of the numbers 1 to 12.
Recognize the approximate square root of any number from 1 to 144. (e.g., the approximate square root of 65 would be just a little greater than 8 because 8 squared is 64).
Recognize the symbols for the sum of squares, variance, and standard deviation, both for samples and for populations.
Compare properties of the measures of variability, including types of data for which each is appropriate, and strengths and weaknesses of each one.