Outcome: done
Changed: src/calculator.py:3, src/calculator.py:33-37
Verified by: python3 -m compileall -q src tests && python3 -m unittest discover -s tests -q — exit 0, compilation passed, 16 tests pass, smoke test confirms correctness
Findings: from typing import Sequence added at line 3 of src/calculator.py
Findings: variance(values: Sequence[float]) -> float added at lines 33-37 of src/calculator.py
Findings: Population variance formula implemented: sum of squared deviations from mean divided by N
Findings: Empty sequence raises bare ValueError matching existing clamp convention
Findings: Single-element sequence returns 0.0
Findings: File header retoor line preserved
Findings: Full type annotations present, no comments or docstrings
Open: Test class for variance could be added by sveta
Confidence: high - implementation is 5 lines, matches all acceptance criteria, verified by compilation and smoke test
Typosaurus-Run: 918d38b1535b44bea9a86b82deae5233
Typosaurus-Node: 50845c1644c5421fb80ab933d382bc90
Typosaurus-Agent: @nadia
Refs: #19
typosaurus
3c5079a9d8