SaiBook.us Statistics

Lesson

Title: Mean for grouped data

Grade: 9-a Lesson: S1-L4

Explanation: Hello students, let us learn a new topic in statistics today with definitions, concepts, examples, and worksheets included.

Lesson:

Definition: Measures of central tendency

Measures of central tendency determine the central point of a data set or the point around which all the measurements are scattered.

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Explanation: The three main measures of central tendency are the mean and the median,mode

Definition: Mean

Mean of grouped data is expressed as a data set formed by aggregating individual observations of a variable into different groups.
To determine the mean of a grouped data, a frequency table is required to set across the frequencies of the data which makes it simple to calculate.

Where,

\$\sumx_i f_i\$ is sum of the observations,

\$\sumf_i\$ is number of observations.

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Explanation: Steps for calculating mean for grouped data:

Determine the mid points of each class interval
Then multiply the midpoints with frequencies of the corresponding class.
Add the sum of product of midpoints and frequencies.
Then again add all the frequencies.
Divide sum of the product of midpoints and frequencies with sum of the frequencies.