As reported by the Pew Research Center’s Social and Demographic Trends Project in September 2012, a survey of 6500 American households revealed that a record 19% owed student loan debt in 2010 (a sharp increase from the 15% that owed such debt in 2007).
a. Calculate and interpret a 95% CI for the proportion of all American households in 2010 that owed student loan debt.
b. What sample size is required if the desired width of the 95% CI is to be at most .04, irrespective of the sample results?
c. Does the upper limit of the interval in part (a) specify a 95% upper confidence bound for the proportion being estimated? Explain.