6. Dogs: Obedience School An obedience school for dogs experimented with two methods of training. One method involved rewards (food, praise); the other involved no rewards. The dogs were randomly placed into two independent groups of 11 each. The number of sessions required to train each of 22 dogs follows.

With rewards 12 17 15 10 16 20 9 23 8 14 10 No rewards 19 22 11 18 13 25 24 28 21 20 21 Use a 0.05 level of significance to test the hypothesis that the number of sessions was the same for the two groups against the alternate hypothesis that the number of sessions was not the same.