Assumed mean method
The assumed mean method is a shortcut for finding the mean of grouped data by taking one convenient central value as a reference.
Practice This ConceptMain explanation
Teacher explanation
When numbers are large, direct multiplication can be lengthy. In the assumed mean method, we choose a class mark as an assumed mean, find deviations from it, multiply deviations by frequencies, and use the formula for mean. It saves time and reduces calculation load.
Example
If 20 is chosen as the assumed mean, then deviations are found from 20 and used to compute the mean quickly.
Simple analogy
Assume, deviate, multiply, correct, and finish.
Common confusion
Students forget to add the assumed mean back at the final stage, so the answer becomes incomplete.
Exam tip
Choose a class mark near the center of the data to keep deviations small and calculations simple.
Answer writing and exam use
1-mark use
Write the exact meaning of assumed mean method in one clean line.
2-mark use
Define assumed mean method and add one example or condition.
3-mark use
Explain assumed mean method, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.
Help improve this page
Found something confusing, incorrect, or missing?