A researcher obtains data for witch
Xbar1 =16.63 s1 =1.42 n1=12
Xbar2 =17.93 s2 =3.16 n2=18
1 = control group
2= experimental group
a) Obtain a 95% confidence interval estimate for population varience, the standard deviation of the experimental group.
b) Test the hypothesis that the experiment was effective at the alpha=0.05 significance.