Descriptive Stats 9.1

Descriptive Statistics

branch of statistics concerned with describing sets of measurements including samples and populations

Population

group that data collected represents

Sample

group data is collected from

Variable

characteristics that vary or change over time

Data

variables under observation that are collected

Data Set

a set of measurements of a specified characteristic

Numerical Data

quantitative variables that measure a numerical quantity or amount

Discrete Numerical Data

results from counting

Continuous Numerical Data

results from measuring

Categorical (Qualitative Data)

measures a quality/characteristic of what you are experimenting
displayed in order it is collected (raw form) or ordered array (numerical order)

Frequency

how often a variable occurred

Mid-interval value

midpoint of each interval class

Frequency Histogram

shows frequency distributions, height of each bar is equal to the number of observations

Cumulative Frequency Distribution

total number of observations whose values are less than the upper limit of each interval

Relative Cumulative Frequency Distribution

cumulative frequencies converted to cumulative percentages