A group of doctors published an article in the New England Journal of Medicine. In the article they revealed the findings of a study to determine if there is a difference in survival rates for men who undergo surgery for localized prostate cancer and those who are treated with observation only. The researchers randomly assigned 731 men with localized prostate cancer to radical prostatectomy or observation. During the years of follow-up, 245 of 367 (66.8%) assigned to surgery survived for at least 5 years and 223 of 364 men (61.3%) assigned to observation survived for at least 5 years. Required:
a. Construct and interpret a 99% confidence interval for the difference in the true proportion of men like these that would survive for at least 5 years after receiving surgery and the proportion that would survive for at least 5 years when only being observed.
b. How does the confidence interval from part a tell you that there is not sufficient evidence at the a=.01 level that there is a difference in the proportion of men with localized prostate cancer who survive at least five years after receiving surgery and the proportion of men with localized prostate cancer who survive at least five years when only being observed. In other words, how would you know that the p-value for a 2 proportion z test would not be significant at the 0.01 level?

Damon makes 20 cups of lemonade by mixing lemon juice and water. the ratio of lemon juice to water is shown in the tape diagram. lemon juice\text{lemon juice} lemon juice water\text{water} water how much lemon juice did damon use in the lemonade? cups

In january 2010, you began a one-year study of tuberculosis (tb) in a subsidized housing community in the lower east side of new york city. you enrolled 500 residents in your study and checked on their tb status on a monthly basis. at the start of your study on january 1st, you screened all 500 residents. upon screening, you found that 30 of the healthy residents had been vaccinated for tb and therefore were not at risk. another 20 residents already had existing cases of tb on january 1st. on february 1st, 5 residents developed tb. on april 1st, 10 more residents developed tb. on june 1st, 10 healthy residents moved away from new york city and were lost to follow-up. on july 1st, 10 of the residents who had existing tb on january 1st died from their disease. the study ended on december 31, 2010. assume that once a person gets tb, they have it for the duration of the study, and assume that all remaining residents stayed healthy and were not lost to follow-up. is the subsidized housing community in the lower east side of new york city a dynamic or fixed population? briefly explain the rationale for your answer. dynamic population it can changeable people can move out and move in into the population of a subsidized housing what was the prevalence of tb in the screened community on january 1st? prevalence = 30/500 0.06= 6% what was the prevalence of tb on june 30th? prevalence= 40/450=0.08= 8.88% what was the cumulative incidence of tb over the year? cumulative incidence = number of new cases/number in candidate population)over specified time period 10/450 = 2.2% suppose that you wanted to calculate the incidence rate of tb in the study population. calculate the amount of person-time that would go in the denominator of this incidence rate. be sure to show your work.

Aubrey read 29 books and eli read 52 books what number is equal to the number of books aubrey read