Populations, Samples, and Processes
population
a well-defined collection of objects
census
desired information is available for all objects in the population
a sample
a subset of the population
a variable
any characteristic whose value may change from one object to another in the population
univariate data
consists of observations on a single variable
bivariate data
consists of observations on two variables
multivariate data
consists of observations on more than variables
descriptive statistics
graphical
histograms
boxplots
scatter plots
numerical
means
standard deviations
correlation coefficients
inferential statistics
Techniques for generalizing from a sample to a population<br>The population as consisting of all possible data that might <br>be made under similar experimental conditions. Such a population<br>is referred to as a conceptual or hypothetical population. There are <br>a number of problem situations in which we fit questions into the <br>framework of inferential statistics by conceptualizing a population. <br>
The relationship between probability and inferential statistics
Measures of Variability
Range
difference between the largest and smallest sample values
Deviations from the mean
Sum of deviations
样本方差和样本平方差
