Javelin. Brianna, a member of the track team, runs an experiment to test how different factors affect her javelin throw. She wants to know if the more expensive (premium) javelin is worth the extra price and is curious to know how much warming up helps her distance. She tries all four combinations of the two Javelins (standard and premium) and Preparation (no warm-up-cold-and warm-up), repeating each combination twice in random order. She measures the distance of her throw to the nearest meter. Here are the results of the 8 runs.
a) What are the null and alternative hypotheses for the main effects?
b) Analyze the data and write a short report on your findings. Include appropriate graphics and diagnostic plots and a recommendation for Brianna to optimize her javelin distance.