Nominal Ordinal Interval and Ratio Variables

Variables Data and Scores

Discrete vs Continous

Populations vs Samples

Sampling Error

Descriptive vs Inferential Statistics

Paramters vs Statistics

Frequency Distributions

Frequency Distribution Tables ~ The Basics

Histograms

Bar Charts

Polygons

Frequency Distribution Tables ~ Finding Sample Size n

Frequency Distribution Graphs ~ Shape of a Distribution

The Stem and Leaf Display

Frequency Distribution Tables ~ Proportions and Percentages

Frequency Distribution Tables ~ Grouped Data

Percentiles and Percentile Ranks

Frequency Distribution Tables ~ Finding the Sum of x Σx

Interpolation

The Mean as a Balance Point

How adding a constant to each score affects the mean

When to Use the Median

The Mode

Why the Mean is Best

The Median ~ Example with Continuous Data

The Weighted Mean

What is Central Tendency

How adding a new score or removing a score affects the mean

How multiplying or dividing scores by a constant affects the mean