Fran is training for a marathon and she wonders if she will receive better training is she runs with a group rather than on her own . She wants to know if there is a significant difference in the number of miles run each week between group runners and individual runners . The interviews 32 people that she knows train in groups , and finds that they average 49 miles per week with a standard deviation of 4.2 miles . The also interviews 30 people who she knows that train on their own and finds that they runon average 47.2 miles per week with a standard deviation of 4.8 miles . Test Fran's claim at .05