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
\alpha =2.9,\beta =1.1
, and
\gamma =0.5
. [Hint: The two-parameter Weibull distribution can be generalized by introducing a third parameter
\gamma
, called a threshold or location parameter: replace
x
in the equation below,
f(x;\alpha ,\beta )={((\alpha )/(\beta ^(\alpha ))x^(\alpha -1)e^(-((x)/(\beta ))^(\alpha )),x>=0),(0,x<0):}
by
x-\gamma
and
x>=0
by
x>=\gamma
.] (a) Calculate
P(x>1.5)x