Measures Of Central Tendency

Summation (Σ) Notation

This appears as the symbol, Σ, which is the Greek upper case letter, S. The summation sign, Σ, instructs us to sum the elements of a sequence. A typical element of the sequence which is being summed appears to the right of the summation sign.

Organisation and Presentation of Data (Part 2)

Important points to remember while drawing a chart:

• The title of the graph should be clear.
• Axes should be well labelled. 
• Unit of measure should be clearly stated in the axis.
• A legend is necessary to differentiate between graphs.

Organisation and Presentation of Data

Content:
Simple frequency distribution
Grouped frequency distribution
Cross-tabulation/ Contingency table
Secondary statistics
Stem and leaf

Tabulation

Type of table

1. Frequency table
2. Two-way table/contingency table/cross tabulations
3. General table

Basic data exploring and handling

Content:
Sorting
Ordering
Ranking
Classification
Ratio
Percentage
Rate
standardised rate


Sorting
Sorting is any process of arranging items systematically. Sorting a data is a way of organising data and we can identify different patterns that will not be possible to identify in an unorganised data.

Example:
Raw data (Gender of students)
Male, Female, Male, Female, Female, Female, Male, Female, Male, Male, Female.

Sorted data
Male, Male, Male, Male, Male, Female, Female, Female, Female, Female, Female.

The sorted data make a pattern where you can find that there is more female than male.

Introduction to statistics

What is Statistics?

Statistics is the methodology for collecting, analyzing, interpreting and drawing conclusions from collected data.
Definition 1.1 (Statistics). Statistics consists of a body of methods for collecting
and analyzing data. (Agresti & Finlay, 1997)

Statistical methods can be used to find answers to the questions like:

1. What kind and how much data need to be collected?
2. How should we organize and summarize the data?
3. How can we analyse the data and draw conclusions from it?
4. How can we assess the strength of the conclusions and evaluate their uncertainty?

That is, statistics provides methods for

• Design: Planning and carrying out research studies.
• Description: Summarizing and exploring data.
• Inference: Making predictions and generalizing about phenomena represented by the data.

Content & Recommended books

Topic content:

1. Introduction to statistics
2. Data collection
3. Organisation and presentation of data
4. Measures of central tendency
5. Measures of dispersion and skewness
6. Probability
7. Index number
8. Time series Analysis
9. Correlation and regression

Recommended books:

1. Clarke & Cooke A Basic Course in Statistics Arnold Clarke & Cooke A Basic Course in Statistics Arnold. [Link: http://www.mv.helsinki.fi/home/jmisotal/BoS.pdf]
2. Anderson, Sweeney, Williams Statistics – Concepts and Applications West Publishing Company.
3. Statistics by Frank Owen and Ron Jones.
4. Statistics fot business and economics. [Link: http://www.cengagebrain.co.uk/content/anderson18101_1408018101_01.01_toc.pdf]