This visualization displays average hemoglobin levels by sex, with each horizontal bar showing the mean and a 95% confidence interval computed using the `jStat.tci` function. The chart uses React and D3 v6, with `scaleBand` for the categorical y-axis and `scaleLinear` for the numeric x-axis, rendered as SVG through a reusable `VizContainer`. Data is loaded from a CSV file via `d3.csv`, and the bars include optional confidence-interval lines that are drawn from the lower to upper bound of the interval.