# S1 Statistics Revision - Chapter 2 Notes

Chapter 2 - Representation of sample data

- Created by: Megan Wilkinson
- Created on: 17-05-12 17:25

First 198 words of the document:

AS Statistics Revision

Statistics 1 Chapter 2

Representation of sample data

Key points to remember

Data = a series of observations, measurements or facts.

Variable = that which is measured or observed, e.g. height.

Type of Variable

Quantitative variable = one with measurements as numbers.

Qualitative variable = one to which numbers cannot be

assigned.

Discrete variable = one taking any value within a given range.

Continuous variable = one taking any value within a given

range.

Frequency distribution = shows the values of a variable and

how

often each occurred

Cumulative frequency = obtained by adding frequencies one

at a time across a row of frequencies

e.g. frequency 1 4 8...

cumulative frequency 1 15 13...

Stem and Leaf diagram = each row represents a stem and is

indicated by the number to the left of the vertical line. The

digits

to the right of the vertical line are leaves associated with the

stem

5 0 1 1 2 4

6 0 1 2 6

7 1 2 4 8

Stem Leaf

Grouped frequency distribution = a table in which frequencies

are associated with groups or classes rather than single

observations

Terminology = consider the class 810

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