Question

Once an individual has been infected with a certain disease, let X represent the time (days) that elapses before the individual becomes infectious. An article proposes a Weibull distribution with a=2.3, β=1.8, and γ=0.5. [Hint: The two-parameter Weibull distribution can be generalized by introducing a third parameter _{y}, called a threshold or location parameter: replace x in the equation below,

\(f(x ; \alpha, \beta)=\left\{\begin{array}{cl}\frac{\alpha}{\beta^{a}} x^{a-1} e^{-(x / \beta)^{a}} & x \geq 0 \\ 0 & x<0\end{array}\right.\)

by x-y and x ≥ 0 by x ≥ γ.]

Answer 1