stats

• Statistics


  The science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions
• Data


  Factual information used as a basis for reasoning, discussion, or calculation
• Types of Statistics


  • Descriptive Statistics
  • Inferential Statistics
• Descriptive Statistics


  Organizing and summarizing data through numerical summaries, tables, and graphs
• Descriptive Statistics


  • The average score of a volleyball player for the past 10 games
  • Birth rate in rural areas in the Philippines
  • Enrollment record of all colleges in BSU – TNEU Lipa Campus
• Inferential Statistics


  The logical process that involves generalizing from a sample to the population from which the sample was selected and assessing the reliability of such generalizations
• Inferential Statistics


  • A car manufacturer wishes to estimate the average lifetime of batteries by testing a sample of 50 batteries
  • The political views of the youth in the urban areas with respect to inflation rate in Asia
  • A campaign manager analyzes the effect of TV ads on the promotion of a presidential candidate
• Population


  All the members of the group about which you want to draw a conclusion
• Sample


  A portion or part of the population of interest selected for analysis
• Parameter


  A numerical index describing a characteristic of a population
• Statistic


  A numerical index describing a characteristic of a sample
• Primary data


  Data that come from an original source, and are intended to answer a specific research question
• Secondary data


  Data taken from previously recorded data, such as information in previously conducted research, financial statements, business periodicals, and government reports
• Constant


  A characteristic of objects, people, or events that does not vary
• Constant


  • The temperature at which water boils (100 degree Celsius)
• Variable


  A characteristic of objects, people, or events that can take different values
• Types of Variables


  • Qualitative variables
  • Quantitative variables
• Qualitative variables


  Variables that yield categorical responses, such as words or codes that represent class or category
• Qualitative variables


  • Eye color, sex, occupation, student number
• Quantitative variables


  Variables that take on numerical values representing an amount or quantity
• Quantitative variables


  • Height, weight, distance, salary
• Classification of Variables


  • Experimental Classification
  • Mathematical Classification
• Independent variables


  Variables controlled by the experimenter or researcher, and expected to have an effect on the behavior of the subjects
• Dependent variables


  Variables that measure the behavior of subjects and are expected to be influenced by the independent variable
• Experimental Classification


  • To predict the value of fertilizer on the growth of plants, the dependent variable is the growth of plants while the independent variable is the amount of fertilizer used
• Discrete variables


  Quantitative variables that are either a finite number of possible values or a countable number of possible values
• Discrete variables


  • Number of cars, number of siblings
• Continuous variables


  Quantitative variables that have an infinite number of possible values that are not countable
• Continuous variables


  • Height, weight, volume
• Levels of Measurement of Variables

  • Nominal Level
  • Ordinal Level
  • Interval Level
  • Ratio Level
• Nominal Level


  Data that consist of names, labels or categories only, with no numerical value
• Nominal Level


  • Sex (male or female), Type of School (public or private), Eye Color (blue, green, brown)
• Ordinal Level


  Data that may be arranged in some order, but differences between data values either cannot be determined or meaningless
• Ordinal Level


  • Highest Educational Attainment (elementary, high school, bachelor, masteral, doctoral), Rank of military officer (lieutenant, captain, major, colonel)
• Interval Level


  Measurement level that specifies the distances between each interval on the scale, with no absolute zero
• Interval Level


  • Temperature on Fahrenheit/Celsius thermometer, IQ (e.g., high IQ vs. average IQ vs. low IQ)
• Ratio Level


  The highest, most precise, level of measurement, with an absolute zero
• Ratio Level


  • Height and weight, Time, Distance and speed