chapter  7
37 Pages

## Analysis of Variance

WithDavid L. Trumpower, Sait Atas

Suppose that two scientists develop a baseball bat made of geneticallyengineered wood. The scientists think that their bats will hit baseballs further than bats made of normal wood. To test their hypothesis they devise an experiment in which they use a robotic arm to hit baseballs with exactly the same force. In their experiment they use the robotic arm to hit several randomly selected baseballs with baseball bats made with normal wood, and to hit several other randomly selected baseballs with their baseball bats made with genetically engineered wood in random order. Now, suppose that the distances (in meters) of the balls hit with the two different types of baseball bats were as follows:

Based on these results, do you think that the type of baseball bat really does have an effect on the distances that the baseballs travel? Before answering, consider each of these additional questions:

1. On an average, how much further did the balls hit by bats made with genetically engineered wood travel than the balls hit by bats made with normal wood?