An article summarized results from a national survey of 2202 Americans age 8 to 18. The sample was selected in a way that was expected to result in a sample representative of Americans in this age group.
(a) Of those surveyed, 1227 reported owning a cell phone. Use this information to construct a 90% confidence interval estimate of the proportion of all Americans age 8 to 18 who own a cell phone. (Round your answers to three decimal places.)
(b) Of those surveyed, 1528 reported owning an MP3 music player. Use this information to construct a 90% confidence interval estimate of the proportion of all Americans age 8 to 18 who own an MP3 music player. (Round your answers to three decimal places.)