Answer
Null hypothesis is that the the mean time on the Trail Making Test for schizophrenics is equal to that of normal persons. Hence:
$H_{o}: µ_{1} = µ_{2}$ or $µ_{1} - µ_{2} = 0$
$H_{a}: µ_{1} > µ_{2}$ or $µ_{1} - µ_{2} > 0$
Work Step by Step
As above