Introduction to Statistics

• Statistics


  Branch of science that deals with the following: collection, organization, analysis, interpretation, presentation of data
• Every major decision is backed up by data
• Role of Statistics in Different Fields

  • Medicine - policies were creating using data and statistics
  • Economics - all industries and sectors use data to back up policies
  • Education - comparison of teaching methods
  • Business - consumer goods undergo quality control
• Statistical Inquiry


  Collection, exploration, and analyzation of data to answer a problem
• Stages in Statistical Inquiry

  1. Identify the problem

  2. Plan the study

  3. Collect the data

  4. Explore the data

  5. Analyze the data and interpret the results

  6. Present the Results
• Population


  Collection of all elements, the entire group in which you want to draw conclusions about (in a statistical inquiry)
• Sample


  Subset of a population, all elements of a sample must belong to the population
• Variables


  Characteristic that can be measured and can assume different values depending on the characteristic
• Observation


  Values of the variable
• Data


  Collection of observations
• Summary Measure


  Summary figure that describes the whole collection
• Parameter


  Describes a specific characteristic of a population, computed using population data
• Statistic


  Describes a specific characteristic of a sample, computed using sample data
• Applied Statistics


  Procedures and techniques used in the collection, organization, presentation, interpretation, and analysis of data
• Descriptive Statistics


  Organizing, summarizing, and presenting data on hand
• Inferential Statistics


  Analyzing sample data to generalize a population, drawing a conclusion or an estimation using sample data