Scatter plot of F₃₀ vs. flare 1–8 Å fluence for prompt proton events originating from W20 to W85 heliolongitude (1996–2005; Cliver et al. 2012), with geometric mean power law regression line, for which the equation and correlation coefficient are given. The geometric mean regression line fit was used because the parameters are not thought to be causally related; both are attributed to a fast CME which leads to reconnection and a flare in its wake while driving a shock responsible for the SEP event. The dashed lines are drawn at ±1σ and the position of the 1859 event is indicated.