Chapter 1 – Part A:
Variables and Data Types:
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We can have one or more variables in any statistical study.
Each variable assume many values
The data is the set of all these values.
Population or sample
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The data can be collected from the population (all subjects under study).
But usually it's collected from a sample (group of subjects selected from the population) to save
time and expense or if population is infinite.
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Qualitative (or categorical): Characteristic values (non-numerical) that can be categorized
major, gender, geographic area, religion, zip code, marital status, color,
Course grade (A, B, C,
D, F), size [small, medium, large], performance (poor, average, good)
Quantitative: (Numerical values)
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Discrete: Each value is a counted
number like 0, 1, 2 …etc.
TOEFL, IQ scores
, Exam grade, number of students, number of children, and
number of calls