Question 1168566
Ho: mean before=mean after
Ha: means are not equal (two-tail)
t(0.975,df=11)=2.201

t=(x bar-mean)/s/sqrt(n)
=2.17/3.13/sqrt(32)
=2.17*sqrt(32)/3.13
=3.92
Reject Ho. The means are not the same.

2. reject if t> 2.201 or t<=2.201 given 11 df.

3. see above.
4. same
5. Mild shock affects the rats' performance.