Chapter 13 · Question 5

State the formula for median of grouped data.

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Q5

State the formula for median of grouped data.

Answer Revealed
Direct Answer:
Median =l+n2cff×h=l+\frac{\frac n2-cf}{f}\times h, where ll is lower limit of median class, nn total frequency, cfcf cumulative frequency before median class, ff median class frequency, and hh class size.

Simple Explanation

Find the class whose cumulative frequency first exceeds n/2n/2, then apply the formula.

Exam-Ready Structure

First compute cumulative frequencies and total frequency nn. The median class is the class whose cumulative frequency is just greater than n2\frac n2. Then use Median=l+n2cff×h\text{Median}=l+\frac{\frac n2-cf}{f}\times h.

Key Points

  • Median =l+n2cff×h=l+\frac{\frac n2-cf}{f}\times h, where ll is lower limit of median class, nn total frequency, cfcf cumulative frequency before median class, ff median class frequency, and hh class size.
  • Use the NCERT formula or theorem carefully.
  • Write units and final conclusion where applicable.