1. Stat 301 – Day 38 Putting it all together!

2. Last Time – Bootstrapping with 2 samples With two independent random samples, can bootstrap each sample, calculate the difference in the statistics, and build a bootstrap distribution to get standard error of statistic Observed difference in medians 186

3. Results may vary! Randomization distribution  Some issues with medians  Type of study design mostly affects scope of conclusions

4. Investigation: The Biggest Loser Stat 301 Other data files page Choice of procedures

5. Investigation: The Biggest Loser (a) one-sample z-test (H 0 :  =.5) (b) one-sample z-interval (c) two-sample t-test (d) two-sample z-test for proportions (e) one-sample t-interval (matched pairs) (f) one proportion test on whether lost less (g) one-sample t-interval for a mean (h) one-sample t-prediction interval (i) randomization test?

6. Investigation: The Biggest Loser (j) Each test has a.05 probability of a Type I Error. The chances of making at least one Type I Error across 6 tests rises to.265 Would prefer a procedure that allows you to compare all 4 means at once with a follow-up for adjusting the overall error rate if do find is at least one difference

7. Investigation: The Biggest Loser (k) Where EV = diet and statistically significant Overweight individuals in Boston area who would volunteer for such a study?

8. Investigation: The Biggest Loser Stat 301 Other data files page Choice of procedures Prepare a mini-analysis for the research question, be ready to present your analysis  (a)/(b), (c), (d), (e)/(f), (g)/(h), (i) Solutions online

9. For Friday HW 8 due Review!  Draft handout online Send suggestions for handout Course evaluation Final exam sign up done!