Statistics
the science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.
Population
the entire group to be studied.
Individual
a person or object that is a member of the population being studied.
Sample
a subset of the population that is being studied.
Statistic
a numerical summary of a sample.
Descriptive Statistics
consist of organizing and summarizing data. This describes data through numerical summaries, tables, and graphs.
Inferential Statistics
uses methods that take a result from a sample, extend it to the population, and measure the reliability of the result.
Parameter
a numerical summary of a population.
Data
numeric values that are gathered through measurements and/or observations.
Data Set
a collection of data values.
Data Value (datum)
and individual value in a data set.
Variables
the characteristics of the individuals within the population.
Qualitative, or categorical variables
allow for classification of individuals based on some attribute or characteristic
Quantitative Variables
provide numerical measures of individuals. The values of a quantitative variable can be added or subtracted and provide meaningful results.
Discrete Variable
a quantitative variable that has either a finite number of possible values or a countable number of possible values. The term countable means that the values result from counting, such as 0, 1, 2, 3, and so on. This variable cannot take on every possible
Continuous Variable
a quantitative variable that has an infinite number of possible values that are not countable. This variable may take on every possible value between any two values.
Qualitative Data
observations corresponding to a qualitative variable.
Quantitative Data
observations corresponding to a quantitative variable.
Discrete Data
observations corresponding to a discrete variable.
Continuous Data
observations corresponding to a continuous variable.
Nominal level of measurement
this happens if the values of the variable name, label, or categorize. In addition, the naming scheme does not allow for the values of the variable to be arranged in a ranked or specific order.
Ordinal level of measurement
this happens if the variable has the properties of the nominal level of measurement, however the naming scheme allows for the values of the variable to be arranged in a ranked or specific order.
Interval level of measurement
this happens if the variable has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero does not mean the absence of the quantity. Arithmetic operations such as addition and subtr
Ratio level of measurement
this happens if the variable has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero means the absence of the quantity. Arithmetic operations such as multiplication and division ca