A poll conducted in 1972 asked 1009 people, "During the past year, about how many books, either hardcover or paperback, did you read either all or part of the way through?" Results of the survey indicated that x= 18.9 books and s= 19.9 books. (a) Construct a 99% confidence interval for the mean number of books read either all or part of during the preceding year. Interpret the interval. (b) Compare these results to a recent survey of 1009 people. The results of the survey indicated that x= 13.1 books and s= 16.2 books. A 99% confidence interval for this survey is (11.78, 14.42). Were people reading more in 1972 than they are today? а г Click the icon to view the table of areas under the t-distribution. (a) The 99% confidence interval for 1972 is (.). (Use ascending order. Round to two decimal places as needed.) Interpret the confidence interval. Which of the following is correct? (b) Were people reading more in 1972 than they are today? O A. Yes, people were reading more in 1972 than they are reading today, because the confidence intervals do not cross and have no common outcomes. O B. No, people were reading less in 1972 than they are reading today because the confidence intervals do not cross and have no common outcomes. O C. People were reading approximately the same number of books in 1972 as they are today because the intervals cross and have some common outcomes.

The figure to the right shows the results of a survey in which 1018 adults from Country​ A, 1025 adults from Country​ B, 1005 adults from Country​ C, 999 adults from Country​ D, and 999 adults from Country E were asked whether national identity is strongly tied to birthplace. Construct a 95​% confidence interval for the population proportion of adults who say national identity is strongly tied to birthplace for each country listed. The 95​% confidence interval for the proportion of adults from Country A who say national identity is strongly tied to birthplace is (____),(____) The 95​% confidence interval for the proportion of adults from Country B who say national identity is strongly tied to birthplace is (____),(____) The 95​% confidence interval for the proportion of adults from Country C who say national identity is strongly tied to birthplace is (____),(____) The 95​% confidence interval for the proportion of adults from Country D who say national identity is strongly tied to…

Construct a 95% confidence interval for p1 - p2 for a survey that finds 30% of 240 males and 41% of 200 females are opposed to the death penalty. Group of answer choices a.(-0.200, -0.021) b.(-1.532, 1.342) c.(-1.324, 1.512) d.(-0.561, 0.651)

During the 2009 holiday season, 436 randomly sampled American adults were surveyed regarding their average spending on Black Friday. A 95% confidence interval based on this sample is ($80.31,$89.11). (c) Determine the sample mean x and the sample standard deviation s of the sample. (d) Which would be the confidence level corresponding to an interval ($81.27,$88.15) for the data found in (c)? (e) If the values of the sample mean and sample standard deviation found in (c) do not change, find the sample size N for which a 99% confidence interval would have a margin of error smaller than 5.