FIGURE 3.

COVID‐19 data analysis result Note. Upper: twice of log‐likelihood ratio, $2[{\max }_{\mathit{\theta },\pi }\ell (\mathit{\theta },\pi )-{\max }_{\mathit{\theta }}\ell (\mathit{\theta },\pi )]$, versus π. The dashed line is at 2.71, the 90% quantile of chi‐squared distribution with 1 degree of freedom. In fact, the horizontal ordinate of the crossover point is the 95% upper bound of π by likelihood ratio, since $0.5+0.5{\chi }^2(2.71,1)=0.95$ (mixed chi‐squared distribution), where ${\chi }^2(·,1)$ is the cdf of chi‐squared distribution with 1 degree of freedom. Lower: incubation estimation; red line: forward time fit; blue line: incubation period fit; black line: mixed observed time fit (covered by the red line). This figure appears in color in the electronic version of this paper, and any mention of color refers to that version.