basic definitions statistics collect organize analyze summarize interpret information - data draw...

Basic Definitions Statistics

Collect Organize Analyze Summarize Interpret Information - Data Draw conclusions

Basic Definitions Population - Sample

Population Sample Parameters µ σ ρ Statistics x s p

Basic Definitions Descriptive - Inferential

Descriptive– Graphs and charts– Numerical representations

– Central Tendency– Variability– Location

Inferential– Confidence Intervals– Hypothesis Testing

Basic Definitions Descriptive - Inferential

Descriptive

Probability

Inferential

Basic Definitions Variables - Measurement

Variables discrete – continuous Variable values Variables independent - dependent Scales

– Nominal– Ordinal– Interval– Ratio

Frequency Distribution Tables

Table with two entries:– Variable values– Number of occurrences of each value

Grouped frequency distribution tables Ungrouped frequency distribution tables Relative Frequencies Cumulative frequencies

Frequency Distribution Graphs

Horizontal line Variable values Vertical line Frequencies

Frequency Distribution Graphs

Bar Graph (discrete/nominal variables)

Histogram (continuous variables)

Frequency Polygon (middle points top of histograms)

Ogive (ptq)

Measures of Central Tendency

The Mean (arithmetic average) The Median (middle value) The Mode (most frequent value) Which one? Central Tendency and shape of

distribution

Measures of Variability

The Range The Population Variance and Standard

Deviation The Sample Variance and Standard

Deviation

Measures of Location

Z-scores and Location Percentiles Box Plots