**Review: Core Concepts, Chs. 1-5**

** Frequency distribution: **Shows the relative frequency of different scores on a variable. Can be
graphically represented as scores "piled up" along a number line of values.

** Variables: **Discrete or continuous, play "dependent" or "independent" roles . Can be measured
on different scales.

** Central tendency: **For inferential stats, the mean, which summarizes information from ALL
scores, is the most important. The location of the mean is affected by skew.

** Variability: **Most important are variance and standard deviation. Both reflect information from
ALL scores.

** Z-scores:** Show the location of individual scores in a frequency distribution. Used to
"standardize" scores.

**Core Skills, Chs. 1-5**

1. Organize a set of scores into a frequency distribution table or histogram

2. Identify the key features of a distribution by looking at a histogram

3. Calculate the mean

4. Calculate the variance and standard deviation

5. Transform X scores into Z scores and vice versa