Unit 1: Introduction
|• Statistics is the Science of Data.|
• Descriptive Statistics summarize and describe data.
• Inferential Statistics enable us to make conclusions and decisions about data.
|• A Population includes all members of a group.|
• A Sample is selected members that (hopefully) represent the Population.
• A Parameter is a measurement of the Population, which
• A Statistic is a measurement of the Sample.
1.3 Scales of Measurement
|• Nominal: Categories|
• Ordinal: Categories with order
• Interval: Numbers with equal distance between points
• Ratio: Numbers with equal distance between points and a meaningful zero.
|• Use 7 to 15 rows, with consistent interval width.|
• x is observations, f is frequency, cf is cumulative frequency, % is percentage, cum% is cumulative percentage.
• Sort scores or score intervals from high to low.
• Calculate cf from the bottom – up.
• % = f divided by total.
• cum% = cf divided by total
• First row of cf should equal the total number of observations.
• First row of cum% should be exactly 100%.
• The lowest and highest score or score interval must have a frequency other than zero.
• All possible scores or score intervals between the lowest and highest must be reported.
(How to by DataScienceCentral)
1.5 Algebra Review
|• Order of Operation|
• Rounding Off