A researcher compared the performance on SAT items of a group of 17 students who were answering questions about a passage after having read the passage, with the performance of a group of 17 students who had not seen the passage. For the first group, the mean was 69.6 and the standard deviation was 10.6. For the second group, the mean was 46.6 and the standard deviation was 6.8. Did these groups significantly differ? Test at .05