Histogram for Exam Scores — Grade Distribution & Bell Curve Analyzer
An exam score histogram groups individual student marks into contiguous score brackets (e.g., $60\text{–}69, 70\text{–}79, 80\text{–}89, 90\text{–}100$) to visualize class performance dispersion and normality.
Tip: Paste Excel or Google Sheets rows (Ctrl+V / ⌘V) directly into any cell.
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Total class size: N = sum(n_i). Pass rate (>= 60): Pass% = (sum_{score>=60} n_i / N) * 100%. Mean students per bracket = N / k.
Chart Design & Use-Case Tips
- 01Total class size: N = sum(n_i). Pass rate (>= 60): Pass% = (sum_{score>=60} n_i / N) * 100%. Mean students per bracket = N / k.
- 02Use uniform 10-point score bins (50–59, 60–69, 70–79, 80–89, 90–100) corresponding to standard letter grade tiers (F, D, C, B, A).
- 03A left-skewed histogram (long tail on the left, peak in the 80s) indicates high subject mastery, whereas a bimodal peak suggests two distinct preparation levels.
- 04Pair with the Box Plot for Test Score Quartiles to compare multiple course sections side-by-side.
Frequently Asked Questions
What does a bimodal exam histogram tell an instructor?+
Two peaks (for example at 62 and 88) usually indicate a split between students who mastered foundational prerequisites and those who struggled early on.
How can I export this chart for a syllabus or department report?+
Click Export 300-DPI PNG or Export Vector SVG to download a clean graphic with axis labels and student counts.
Can I customize the score bracket labels?+
Yes, edit any row label in the Data Workbench to use points (70–79), percentages, or letter grades (A, A-, B+, B).