STATISTICS
Statistics is a method of collecting, organizing and
analyzing data.
Data means raw fact or basic information usually in
number form. Singular for Data is Datum.
Statistics is useful in our everyday life for decision
making, prediction and information.
Data Organisation and
Frequency Tables
Data
can be arranged in an increasing or decreasing order of magnitude to make them
more meaningful. The frequency of an event (anything) is the number of times it
occurs in a given set of data.
Tally system makes use of strokes to represent
frequencies.
Example
An
English teacher gave a spelling test to her class of 30 pupils and obtained the
following data of their scores
2 3 5 3 4 6 8 8 2 6
4 7 4 5 9 9 7 4 4 7
3 3 6 8 6 7 6 3 5 3
Represent
the data on a tally-frequency table.
Steps
(i) Make
3 columns for marks, tally and frequency respectively.
(ii) List
out the different possible marks in the marks column.
(iii) Pick the items in the data one after the other and make tally
marks in each case at the appropriate row to represent the data.
(iv) Count the number of tally against each mark, this gives the
frequency of each mark.
|
Marks
|
Tally
|
Frequency
|
|
2
|
||
|
2
|
|
3
|
|
6
|
|
4
|
|
5
|
|
5
|
|||
|
3
|
|
6
|
|
|
|
7
|
|
|
|
8
|
|
|
|
9
|
|
|
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