statistics
posted by virna .
suppost we wanted to test the hypothesis that control a group of cancer patients(group 1) would report higher mean pain ratings than an experimental group recieving special message treatment(group 2). Use the following information, Compute at a tstatistice for independent group;
mean group 1=78.5 s(square/1)=42.1 and n(1)=25
mean group 2=72.1 s(square2/2)=39.7 and n(2) =25

Use an independent groups ttest for your two samples. n1 + n2  2 degrees of freedom is used for this test. Use a ttable to determine your cutoff or critical value to reject the null (you should have a significance level set for the test). If your test statistic exceeds the critical value from the table, reject the null and conclude a difference. If the test statistic does not exceed the critical value from the table, do not reject the null. You cannot conclude a difference in this case.
I hope this will give you a few hints to get started on your problem.