Introduction to Statistics

• Statistics

  • Science that studies current data to make decisions. This involves collecting, processing, summarizing, and analyzing.
• Statistical Process:

  1. Planning (Sampling) - getting the representative
  2. Collecting the data
  3. Verifying the data - if data qualifies to make a good decision
  4. Summarizing the results
  5. Examining the data
• Illustrating a Random Variable

  • Experiment - is any movement that should be possible more than once under comparative conditions.
  • Random Variable - is a numerical quantity that is assigned to the outcome of an experiment. It assumes numerical values associated with the events of an experiment.
• Two Types of Random Variables

  1. Continuous Random Variable - deals with infinite numbers. Uses a certain measuring tool to measure.
  2. Discrete Random Variable - deals with a set of finite numbers. The set of possible outcomes from an experiment can be counted.
• Finding the Possible Values of a Random Variable

  • Universe - the collection or set of units or entities from whom we got the data.
  • Variable - a characteristic that is observable or measurable in every unit of the universe.
  • Population - the set of all possible values in a variable.
  • Sample - a subgroup (subset) of a universe or a population.
• Values of Random Variable

  A) Sample

  B) Population

  C) Universe

  
• Statistical Experiment

  • an activity that will produce outcomes or a process that will generate data. The outcomes have a corresponding chance of occurrence.
• Sample Size

  • set of all possible outcomes in an experiment.
  • It can be expressed through:
  • Listing
  • Table
  • Tree Diagram