5
O
where F(u,v) = F(v,u) for every (u,v) in R The
parameters y ^ (p 2) and (a 2) ate location and
scale paratmeters, respectively. They are not
necessarily the mean and standard deviation of the
marginal distributions.
A3. Cj,C2*..,C are i.i.d. continuous random
variables, with continuous distribution function
G(c) .
A4. The censoring random variable is independent
f I
of i=l2 n and the value of is
the same for both members of a given pair.
A 5. P(xJi>C.,X2i>Ci) < 1.
A6. G (F ^ )) < 1 where F^ denotes the marginal
i i
T
cumulative distribution function (c.d.f.) of X^^
i=l,2.
Note that under A5, the probability is positive that the
sample will contain observations that are not doubly
censored.
With this notation, the null and alternative hypotheses
can now be formally stated. The null hypothesis is
Hq : y^=P2> 1=ct2 versus the alternatives: