A Wald test can be performed with the samples already done to determine the
MLE. If the constraints imposed in the null hypothesis are of the form
and 
, and 
is the
(observed or expected) Fisher information, then the Wald test statistic is
where 
is the MLE in the alternative hypothesis.
In our example, the constraint is simply 
, so
. So the formula simplifies to
where 
is the second component of the MLE
and 
is the 2,2 component of the
inverse Fisher information (1.44). This gives
.