Grouped Frequency Calculator
Build a frequency table from class intervals and counts. Find relative and cumulative frequencies, a midpoint mean estimate and a histogram that supports unequal class widths.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Find each class midpoint and multiply it by that class’s frequency. Divide their sum by total frequency for an estimated mean. Divide counts by the total for relative frequencies. Histogram height is count divided by class width, so bar area represents count even when widths differ.
Estimated mean=Σ(midpoint×frequency)/Σfrequency; relative frequency=f/N; density=f/class width
Worked example
Classes [0,10), [10,20), [20,30] with counts 3,5,2 have total 10 and relative frequencies 30%,50%,20%. Their midpoint mean estimate is (5×3+15×5+25×2)/10=14. Both central observations are in the second class.
Assumptions and input details
Enter 1–20 ordered, contiguous classes, each as lower bound, upper bound, count. Bounds accept the documented six-place decimals or fractions within ±1e6; counts must be nonnegative whole numbers with total 1–1e9. Intervals are lower-inclusive and upper-exclusive, except the final upper bound is included. Use your own consistent measurement unit. The actual raw values, exact mean and exact median cannot be recovered from grouped counts. For even totals the two central ranks can occupy different classes. Modal classes use frequency density to compare unequal widths.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Midpoint mean and class boundaries use exact fractions. The midpoint mean is an estimate of the raw-data mean; percentages, densities and the histogram are rounded.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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