3. Introduction
• Data are a set of facts, and provide a partial picture of
reality. Whether data are being collected with a certain
purpose or collected data are being utilized, questions
regarding what information the data are conveying, how
the data can be used, and what must be done to include
more useful information must constantly be kept in mind.
•
4. Classification of data
The process of arranging data into homogenous groups or classes according to
some common characteristics present in the data is called classification.
7. TABULATION OF DATA
The process of placing classified data into tabular form is known as
tabulation. A table is a symmetric arrangement of statistical data in
rows and columns. Rows are horizontal arrangements whereas
columns are vertical arrangements. It may be simple, double or
complex depending upon the type of classification.
12. Histogram
• A histogram is a graphical display of data using bars of different heights. In
a histogram, each bar groups numbers into ranges. Taller bars show that
more data falls in that range. A histogram displays the shape and spread of
continuous sample data.
13. Frequency Polygon
A frequency polygon is a graph constructed by using lines to join the
midpoints of each interval, or bin. The heights of the points represent
the frequencies. A frequency polygon can be created from the histogram or
by calculating the midpoints of the bins from the frequency distribution
table.
14. CUMULATIVE FREQUENCY POLYGON
• AN OGIVE (OH-JIVE), SOMETIMES CALLED A CUMULATIVE FREQUENCY POLYGON, IS A TYPE OF FREQUENCY
POLYGON THAT SHOWS CUMULATIVE FREQUENCIES. IN OTHER WORDS, THE CUMULATIVE PERCENTS ARE
ADDED ON THE GRAPH FROM LEFT TO RIGHT. AN OGIVE GRAPH PLOTS CUMULATIVE FREQUENCY ON THE Y-
AXIS AND CLASS BOUNDARIES ALONG THE X-AXIS.
15.
16. SIMPLE BAR CHART
• SIMPLE BAR CHART IS USED TO REPRESENT DATA INVOLVING ONLY ONE VARIABLE CLASSIFIED ON A
SPATIAL, QUANTITATIVE OR TEMPORAL BASIS. IN A SIMPLE BAR CHART, WE MAKE BARS OF EQUAL WIDTH
BUT VARIABLE LENGTH, I.E. THE MAGNITUDE OF A QUANTITY IS REPRESENTED BY THE HEIGHT OR LENGTH
OF THE BARS.
17. Multiple bar Chart
A chart depicting two or more characteristics in the form of bars of length
proportional in magnitude of the characteristics. For example, a chart comparing
the age and sex distribution of two populations may be drawn with sets of bars,
one bar of each pair for each population, and one pair for each age group.
18. COMPONENT BAR CHART
A sub-divided or component bar chart is used to represent data in
which the total magnitude is divided into different or components. In
this diagram, first we make simple bars for each class taking the total
magnitude in that class and then divide these simple bars into parts
in the ratio of various components.
19. Pie Chart
• A pie chart is a circular statistical graphic, which is divided into slices to illustrate numerical
proportion. In a pie chart, the arc length of each slice, is proportional to the quantity it
represents.