(a) What proportion of the smokers were dead after 20 years? What proportion of the nonsmokers were dead after 20 years? What does this imply about the health consequences of smoking? The proportion of the smokers who were dead after 20 years is (Round to three decimal places as needed.) The proportion of the nonsmokers who were dead after 20 years is (Round to three decimal places as needed.) What does this imply about the health consequences of smoking? This implies that it is healthier to smoke. This implies that it is healthier not to smoke. (b) The data in the first table do not take into account a variable that is strongly related to survival status, age. The data shown in the second accompanying table give the survival status of women and their age at the beginning of the study. For example, 14 women who were 35 to 44 at the beginning of the study were smokers and dead after 20 years. Determine the proportion of 18- to 24-year-old smokers who were dead after 20 years. The proportion of 18- to 24-year-old smokers who were dead after 20 years is (Round to three decimal places as needed.) Determine the proportion of 18- to 24-year-old nonsmokers who were dead after 20 years. The proportion of 18- to 24-year-old nonsmokers who were dead after 20 years is (Round to three decimal places as needed.) (c) Repeat part (b) for the remaining age groups to create a conditional distribution of survival status by smoking status for each age group.

Education influences attitude and lifestyle. Differences in education are a big factor in the "generation gap." Is the younger generation really better educated? Large surveys of people age 65 and older were taken in n1 = 38 U.S. cities. The sample mean for these cities showed that x1 = 15.2% of the older adults had attended college. Large surveys of young adults (age 25 - 34) were taken in n2 = 37 U.S. cities. The sample mean for these cities showed that x2 = 18.1% of the young adults had attended college. From previous studies, it is known that ?1 = 6.4% and ?2 = 4.8%. Does this information indicate that the population mean percentage of young adults who attended college is higher? Use ? = 0.05. What is the value of the sample test statistic? (Test the difference ?1 − ?2. Round your answer to two decimal places.)=__(c) Find (or estimate) the P-value. (Round your answer to four decimal places.)=__

In a study of how depression may affect one's ability to survive a heart attack, the researchers reported the ages of the two groups they examined. The mean age of 2397 patients without cardiac disease was 69.8 years, while for the 450 patients with cardiac disease, the mean age was 74.0, respectively. Furthermore, 32% of the diseased group were smokers, compared with only 23.7% of those free of heart disease. (1) Determine a 96% confidence interval for the difference in the proportions of smokers in the two groups. (ii) Indicate whether the two groups in the study were different. State the assumptions in order to proceed with the confident interval construction. (ii)

The price of a share of stock divided by the company's estimated future earnings per share is called the P/E ratio. High P/E ratios usually indicate "growth" stocks, or maybe stocks that are simply overpriced. Low P/E ratios indicate "value" stocks or bargain stocks. A random sample of 51 of the largest companies in the United States gave the following P/E ratiost. 9 20 11 35 19 13 15 21 29 53 16 26 21 14 21 27 10 12 47 14 40 18 60 72 33 14 8 49 5 16 8 19 12 31 67 51 26 18 17 20 19 13 25 23 27 44 20 27 19 18 32 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean x and sample standard deviation s. (Round your answers to one decimal place.) (b) Find a 90% confidence interval for the P/E population mean u of all large U.S. companies. (Round your answers to one decimal place.) lower limit upper limit (c) Find a 99% confidence interval for the P/E population mean u of all large U.S. companies. (Round your answers to one decimal place.) lower limit upper…

Education influences attitude and lifestyle. Differences in education are a big factor in the "generation gap." Is the younger generation really better educated? Large surveys of people age 65 and older were taken in n1 = 38 U.S. cities. The sample mean for these cities showed that x1 = 15.2% of the older adults had attended college. Large surveys of young adults (age 25 - 34) were taken in n2 = 37 U.S. cities. The sample mean for these cities showed that x2 = 18.1% of the young adults had attended college. From previous studies, it is known that ?1 = 6.4% and ?2 = 4.8%. Does this information indicate that the population mean percentage of young adults who attended college is higher? Use ? = 0.05. (c) Find (or estimate) the P-value. (Round your answer to four decimal places.) A random sample of n1 = 12 winter days in Denver gave a sample mean pollution index x1 = 43. Previous studies show that ?1 = 15. For Englewood (a suburb of Denver), a random sample of n2 = 16 winter days gave a…

Tourism is extremely important to the economy of Florida. Hotel occupancy is an often-reported measure of visitor volume and visitor activity (Orlando Sentinel, May 19, 2018). Hotel occupancy data for February in two consecutive years are as follows. Current Year Previous Year Occupied Rooms 1,360 1,386 Total Rooms 1,700 1,800 a. Formulate the hypothesis test that can be used to determine whether there has been an increase in the proportion of rooms occupied over the one-year period. Let pi = population proportion of rooms occupied for current year Pa= population proportion of rooms occupied for previous year Ho : Pi - Pa H.: Pi - P2 Select your answer Select your answer b. What is the estimated proportion of hotel rooms occupied each year (to 2 decimals)? Current year Previous Year c. Conduct a hypothesis test. What is the p-value (to 4 decimals)? Use Table 1 from Appendix B. p-value - Using a 0.05 level of significance, what is your conclusion? We Select your answer- vthat there has…

Check My Work (5 remaining) Each year, over 2 million people in the United States become infected with bacteria that are resistant to antibiotics. In particular, the Centers of Disease Control and Prevention has launched studies of drug-resistant gonorrhea (CDC.gov website). Of 142 cases tested in Alabama, 9 were found to be drug-resistant. Of 268 cases tested in Texas, 5 were found to be drug-resistant. Do these data suggest a statistically significant difference between the proportions of drug- resistant cases in the two states? Use a 0.02 level of significance. What is the p-value, and what is your conclusion? Test statistic = (to 2 decimals) p-value = (to 4 decimals) Conclusion: Reject the null hypothesis Choose the correct option. There is a significant difference in drug resistance between the two states. Alabama has the higher drug resistance rate. True

You conduct a survey of current exposure to organochlorine pesticides and pregnancy status among 500 fertility patients at a fertility center following them from 2015-2017.  Half of those patients are pregnant at the time of survey.  Of those who are pregnant, 63 reported using OCPs in their gardens in the last year while they were trying to conceive.   Among those who are not pregnant at the time of survey, 40% reported using OCPs in their gardens in the last year while they were trying to conceive.  Assume minimal loss to follow-up and no competing risks.  a.  Which study design is described above? Case-control study Closed cohort study Open cohort study Cross-sectional study Ecologic study None of the above B. Draw a 2x2 table based on the description above. Identify and label the exposure and the outcome. Be sure to include any appropriate totals based on the respective study design.