Worked on the scikit-hep/awkward repository to enhance the reliability of statistical computations, specifically focusing on the ak.mean function for weighted means. Addressed a bug affecting the correct handling of keepdims and mask_identity parameters, ensuring that weighted mean calculations now produce accurate and predictable results. Developed comprehensive tests in Python to validate parameter behavior and cover edge cases, which improved test coverage and safeguarded against regressions in related statistical functions. Applied skills in data analysis, numerical computing, and testing to align the implementation with quality assurance standards, thereby supporting reproducibility and clarity in downstream statistical analyses using the library.