Question

In Vienna, Eliud Kipchoge became the first athlete to run a marathon in less than two hours. Kipchoge wore a special type of shoe developed by Nike called Vaporfly that is different than all previous running shoes. It has a much thicker midsole and has a layer of carbon fiber to bounce back as much energy as possible. Nike engineers claim that Vaporfly is significantly faster than any other shoe. Specifically, they claim that Vaporfly improves anybody’s running time by 4% compared to the company’s best running shoes.

A) Design an experiment to validate Nike's claims of 4% improvement.


B) Suppose you have running times for 1275 runners who completed the Boston Marathon in 2017 and 2018. Of the 1,275 runners who run Boston for both years 52 switched to Vaporflys in 2018. You have compared 2018 vs 2017 running times for all 1275 athletes and it is clear that most of those 52 runners who switched to Vaporflys have faster times in 2018 compared to 2017. On average the persons who switched to vaporflys improved their time by 5%. Do you conclude that wearing Vaporfly makes you run faster or do you need additional information to back Nike's assertion of 4% improvement? If you do need additional information state what additional calculations you need to do.

Answer 1