Basic Statistics & Use of Minitab英文(ppt 35页)

Statistics is the branch of science that deals with the collection, presentation, analysis & interpretation of data for the purpose of decision-making and problem-solving.
Statistics is a critical skill in quality improvement as statistical techniques can be used to describe and to understand variability.
Variability is the result of changes in the conditions under which observations are made.
Variability can come about due to changes in
material quality
machine settings or conditions
manpower standards
methods of processing
measurement
milieu (environment)
Population
the entire set of measurements of interest
Sample
  a subset of data from the population
Parameters
  numerical measures of a population
Statistics
  numerical measures of a sample
Whether there are gaps between successively observed values of a variable.
Discrete Variable
gaps exist between observations
obtained by counting
Continuous Variable
no gaps exist between observations
obtained by measuring