45. What is the proportion of all US adults over the age of 60 who live alone? In a recent study, 68 out of 200 randomly selected US adults over the age of 60 indicated that they lived alone. Calculate a confidence interval for the proportion of US adults over the age of 60 who live alone, at the 95% confidence level, following the steps below. Write the correct letter on the line next to each multiple-choice question. a) (2 points) The confidence interval is centered at: A. p. B. p. C. U. b) (2 points) The confidence interval is: A. (0.274,0.406) B. (0.339,0.341) C. (0.307,0.375) c) (2 points) The interval calculated above indicates that: A. Ninety-five percent of US adults over the age of 60 in the population live alone. B. The proportion of US adults over the age of 60 who live alone is a value within that interval, at the 95% confidence level. C. The proportion of adults in the sample who live alone is within the interval in 95% of the cases. 11