ft) is a legitimate probability density. Proof: First, ft) nonnegative for all real 1%. Second, it integrates to 1 as seen here, by using the change of variables y 2 At: / fT(t) dt : :0? A )tu 1? )\\f (it - 700 U F(C:2 A : / (l l e7;;(, :1. 2.4.19 (Weibull(a ) distribution) Consider, for a > 0 fixed, the function given by f( x ) = axa-lexa for 0