Definitions [10]
Frequency:
The number of times a particular observation occurs.
Frequency Distribution:
A tabular arrangement of data showing the frequency of each observation or class.
The two values that bound a class interval.
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Lower limit: Smallest value of the class
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Upper limit: Largest value of the class
The difference between the highest and lowest observations.
Range = Highest value − Lowest value
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Inclusive form: Both lower and upper limits are included in the class.
(Example: 1–10, 11–20) -
Exclusive form: Lower limit is included, but upper limit is excluded.
(Example: 0–10, 10–20)
Statistics is the area of study dealing with the collection, presentation, and analysis of data as well as drawing meaningful conclusions from the data.
A collection of given facts or figures, usually expressed in numerical form.
Each group into which raw data is divided is called a class interval.
Data is a collection of facts, information, or observations, usually in numerical form.
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Example: The heights of all the children in your class.
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Example: The marks obtained by 20 students in a math test.
Raw Data is the information that you have just collected, and it is completely unsorted or unarranged. It's like a messy pile of clothes!
Example (Marks): Imagine a teacher writes the test marks of 15 students on the board:
72, 77, 67, 74, 82, 80, 66, 90, 78, 57, 56, 54, 74, 72, 92
This long list is Raw Data. It's hard to quickly tell who scored the highest or lowest mark.
Answer the following question in about 30 words:
Define the mean.
The mean is the value that is derived by summing all the values and dividing it by the number of observations.
`bar"x" = "Sum of observations"/"No. of observations"`
Formulae [2]
\[\text{Adjustment Factor}=\frac{1}{2}\text{(Lower limit of next class - Upper limit of previous class)}\]
\[\text{Frequency density}=\frac{\mathrm{Frequency}}{\text{Class width}}\]
