MATH 10043 Elementary Statistics

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MATH 10043Elementary Statistics
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Salary Company A
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Definitions

• Statistics (plural) is a synonym for numerical
  facts
• Statistics (singular) is the body of principles
  and procedures developed for the collection,
  classification, summarization, interpretation,
  and communication of numerical data, and for the
  use of such data
• Descriptive Statistics is the part of
  statistics that encompasses the procedures of
  data collection, classification, summarization,
  and presentation
• Statistical Inference is the part of statistics
  that involves procedures for drawing conclusions
  about a population when the data comprise a
  sample selected from the population

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Definitions (cont)

• Population (or universe) is a collection of
  data containing every item connected to the
  variable under investigation
• Sample is a collection of data constituting
  only a part of a population
• Census is a list of all the items in a
  population
• Parameter is a numerical characteristic of a
  population
• Statistic is a numerical characteristic of a
  sample

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Types of Data

• Qualitative Data consist of attributes, labels,
  or non-numerical entries
• Quantitative Data consist of numerical
  measurements or counts

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Types of Data

• Nominal Level of measurement consists of names,
  labels, categories. (ie gender, ethnicity, etc.)
• Ordinal Level of measurement consists of data
  which can be ordered, but differences between
  data values have no meaning. (ie good, better,
  best)
• Interval Level of measurement is an ordinal level
  where the differences are meaningful, but there
  is no zero starting point. (ie temperature, IQ)
• Ratio Level of measurement is an interval level
  with a meaningful zero. (ie height, weight)

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Types of Data

• Discrete data number is either finite or
  countable
• Continuous data infinitely number of possible
  values

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Data Description

• To describe data, three pieces of information
  should be presented
• The size of the sample
• The measure of central tendency
• The measure of variability

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Data Description