matm midterm

• STATISTICS, ORIGIN, AND TERMS
• Statistics


  A collection of methods for planning experiments, obtaining data, and then analyzing, interpreting and drawing conclusions based on the data
• Statistics


  A branch of mathematics that transforms data into useful information for decision makers
• Statistics


  Came from the Latin word status which means state
• Divisions of statistics


  • Descriptive statistics
  • Inferential statistics
• Descriptive statistics


  Summarizes or describes the important characteristics of a known set of data
• Descriptive statistics


  The most common summarizing values are the measure of percentage, central tendency (mean, median, mode) and variation
• Inferential statistics


  Uses sample data to make inferences about the population

  
• Inferential statistics


  Consists of generalizing from samples to population, performing hypothesis testing, determining relationships among valuables, and making predictions

  
• Inferential statistics


  Some of the common statistical tools are the t-test, z-test, analysis of variance, chi-square, and Pearson r
• Data


  Always a result of experiment, observation, investigation and other means and often appears as a numerical figure and then evaluated to make it into useful knowledge
• Data


  Used as facts collected together for reference or analysis
• Classifications of data


  • Quantitative data (numerical)
  • Qualitative data (categorical)
• Quantitative data

  Data can be measured with numbers, such as distance, duration, length, revenue, and speed
• Quantitative data


  • Discrete variables
  • Continuous variables
• Qualitative data


  Non-numerical data that is usually textual and descriptive, like "mostly satisfied," "brown eyes," "female," "yes/no," etc.
• Qualitative data


  • Nominal
  • Ordinal
• Discrete variables

  Values obtained by counting
• Discrete variables

  • Number of pages in a book
  • Number of people in a race
  • Shoe size
• Continuous variables


  Values obtained by measuring, all of which cannot be put into a list because they can have any value in some interval of real numbers
• Continuous variables


  • Length of a film
  • Temperature
  • Time taken to run a race
• Nominal scale


  Classifies elements into two or more categories or classes, the numbers indicating that the elements are different but not according to order or magnitude
• Nominal scale


  The numbers don't define the object characteristics. The only permissible aspect of numbers in the nominal scale is "counting".
• Ordinal scale


  A scale that ranks individuals in terms of the degree to which they possess a characteristic of interest
• Ordinal scale


  Set of categories that are ordered from least to most
• Ordinal scale


  • Miss America results — first place, runner-up, second, third
  • Military rank
  • Letter grade in class
  • Degrees held
  • Medical condition (satisfactory, serious, guarded, critical)
  • Rank order of your preference form 1 to 4 of Ruffles, Doritos, Cheetos, Fritos
• Interval scale


  In addition to ordering scores from high to low, it also establishes a uniform unit in the scale so that any equal distance between two scores is of equal magnitude
• Interval scale


  The data have the properties of ordinal data, and the interval between observations is expressed in terms of a fixed unit of measure
• Interval scale


  This scale has an arbitrary zero point (no absolute value)
• Interval scale


  Interval data are always numeric
• Interval scale


  The interval scale is quantitative as it can quantify the difference between the values
• Interval scale


  It allows calculating the mean and median of the variables
• Interval scale


  • How appealing is this cereal box to children? (-3 to 3)
  • Current temperature
  • Many behavioral science questionnaires
  • IQ
  • Likert Scale
• Ratio scale


  The data have all the properties of interval data and the ratio of two values is meaningful
• Ratio scale


  Variables such as distance, height, weight, and time use the ratio scale
• Ratio scale


  Ratio scale has unique and useful properties. One such feature is that it allows unit conversions like kilogram – calories, gram – calories, etc.
• Ratio scale


  This scale must contain a zero value that indicates that nothing exists for the variable at the zero point
• Ratio scale


  It doesn't have negative numbers, because of its zero-point feature
• Ratio scale


  Only scale that allows you to make ratio comparisons, such as "Maribel's income is 35% more than Susan's"
• Ratio scale


  • Your weight in kilograms
  • Number of times you return to a restaurant after visiting it the first time
  • Amount of money in your checking account
  • Number of questions correct on a quiz
  • Distance from San Antonio to Laredo