The manufacturers of a new running shoe, Blast Off, claim that a new insole material acts as a springboard, launching the runner forward with every step.Researchers would like to determine if there is a difference in the mean speed for runners wearing Blast Off compared to a traditional shoe. They plan to conduct a study with 100 runners.

A random sample of 50 male runners who report that they wear the shoe, Blast Off, and random sample of 50 male runners that run with other shoes will be selected. The researchers ask each of the 100 runners for their fastest 1-mile time on a track and recorded the responses.They will then compare the mean running speed for the two groups.

(a) Is this an observational study or an experiment? Explain.

(b) Explain the concept of confounding in the context of this study. Include an example of a possible confounding variable.

(c) If the mean running speed for those who wear Blast Off is statistically significantly faster than the mean running speed for runners wearing other shoes, could one conclude that the faster running speed is caused by wearing Blast Off shoes? Explain.