 Margaret M. Hilferty

Margaret M. Hilferty coauthored the 1931 paper The Distribution of Chi-Square by Edwin B. Wilson and Margaret M. Hilferty. The original byline identifies her with Harvard's Department of Vital Statistics; no fuller personal name is inferred from the initials.^[ref]

Their Wilson-Hilferty transformation reduces the skewness of a chi-squared distribution by taking a cube root. For $X\sim {\chi }_k^2$, the standardized quantity $((X/k{)}^{1/3}-(1-2/(9k)))/\sqrt{2/(9k)}$ is approximately standard normal. It provides a practical approximation to quantiles and tail probabilities, with accuracy depending on the statistical degrees of freedom and the probability region.^[ref]