An article reported the results of a peer tutoring program to help mildly mentally retarded children learn to read. In the experiment, the mildly retarded children were randomly divided into two groups: the experimental group received peer tutoring along with regular instruction, and the control group received regular instruction with no peer tutoring. There were n1= n2= 30children in each group. The Gates-MacGintie Reading Test was given to both groups before instruction began. For the experimental group, the mean score on the vocabulary portion of the test was , with sample standard deviation s1= 49.1. For the controlgroup, the mean score on the same test was , with sample standard deviation s2= 50.9. Use a 5% level of significance to test the hypothesisthat there was no difference in the vocabulary scores of the two groups beforethe instruction began.