1305AFE Lecture Notes - Lecture 2: Time Series, Ogive, Frequency Distribution
Week 2 Business Data Analysis Lecture Notes
Graphical Descriptive Methods
What is statistics?
• Statistics is a body of principles and methods used to extract useful information from
a data set to assist people to make decisions about questions of interest
• Data are actual observations that result from an investigation or an experiment or a
survey
Two Basic Areas of Statistics
• Descriptive statistics
o Deals with methods of organizing, summarizing and presenting data in a
convenient way
• Inferential statistics
o Is a body of methods for estimating and drawing conclusions about the
population characteristics (population parameters) from a sample taken from
the population.
Descriptive statistics
• Methods of organizing, summarizing, and presenting data in a convenient and
informative way. These methods include:
o Graphical techniques
o Numerical techniques
Summaries data
• Graphical descriptive methods
o Pie and bar charts
o Histograms
o Line chart
o Scatter diagrams
Bar Charts
• Good for qualitative/ nominal data
• Bar charts are most common as they are easier for human eye to distinguish
differences and make comparisons
o Commonly used to graphically represent the frequency of each category
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• Pie charts are commonly used to graphically represent the proportion of each
category
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find more resources at oneclass.com
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Two basic areas of statistics: descriptive statistics, deals with methods of organizing, summarizing and presenting data in a convenient way. Is a body of methods for estimating and drawing conclusions about the population characteristics (population parameters) from a sample taken from the population. Descriptive statistics: methods of organizing, summarizing, and presenting data in a convenient and informative way. These methods include: graphical techniques, numerical techniques. Summaries data: graphical descriptive methods, pie and bar charts, histograms, line chart, scatter diagrams. Frequency polygon: the frequency polygon is obtained by joining the mid points of each class in the frequency histogram. Relative frequency polygon: the relative frequency polygon is obtained by joining the mid points of each class in the relative frequency histogram. Ogive: the ogive curve is obtained by joining the upper limits of each class of cumulative relative frequency histogram. Line chart: good for time series data- quantitative or numerical, show patterns over time.
