A psychologist has developed a set of activities that is intended to help children develop better reading skills. In a study of the effectiveness of these activities, one class of second-grade children learns with the activities. Another class of second-grade children serves as the control and learns without the activities. After some period of time, the reading skills of all of these children were assessed. A summary of these data is:

The psychologist suspects that children who learn with activities have higher mean reading skill test scores than children that don't learn with activities and decides to conduct a relevant test of significance.