1) Are metal bands used for tagging harmful to penguins? Researchers Saraux and colleagues (Nature, 2011) reported the results of a study done to investigate this using a sample of 100 penguins near Antarctica. These penguins had already been tagged with RFID chips, and the researchers randomly assigned 50 of them to receive a metal band on their flippers in addition to the RFID chip. The other 50 penguins did not receive a metal band. Researchers found that 16 of the banded penguins were still living 4.5 years into the study compared to 31 of the unbanded penguins that were still living. Are unbanded penguins more likely to be living after 4.5 years than are banded penguins? Using a theory-based approach, determine the standardized statistic and corresponding p-value. Report answers as provided in the applet (no rounding). Standardized statistic = and p-value =?

2) Researchers Wilt et al. (New England Journal of Medicine, 2012) investigated whether surgery, compared to just observation, was (more) effective in improving men's survival chances after being diagnosed with prostate cancer. The researchers identified men with localized prostate cancer and randomly assigned to surgery and the remaining to observation. All participants were followed for about 10 years. In those 10 years, surgery recipients died of prostate cancer related reasons compared to observation recipients.

A)

Use an appropriate applet to find a theory-based p-value to test the your hypotheses. Report the standardized statistic as well as the p-value. ?The p-value is=? and the standardized statistic is=?

B)

Use an appropriate applet to find a theory-based 99% confidence interval and interpret the resulting interval in the context of the study. We can be 99% confident that the probability of dying of prostate cancer for those that get surgery is between i lower and i higher than those that are just observed for 10 years