Question 1085939
SE=s/ sqrt(n).  I am assuming a=40 is std dev=40
40/sqrt(25)=8, the standard error
z-score is (422-400)/8=22/8=2.75
with alpha=0.01, for a two sided test, z=+/-2.576
The boundaries are 8*2.576=20.608
Critical value or 99%CI=(379.392, 420.608)
The data fall outside the boundaries providing evidence that alcohol significantly increased the reaction time.
==============
with alpha=0.05, use 1.645, since it is one tail
now the upper boundary is 8*1.645+400=413.16
Now the evidence is insufficient to show that there was a difference.
d=(M1-M2)/s=22/8=2.5