an article summarized results from a national survey of 2002 amwericans age 8 to 18. the sample was selected to be representative of americans in this age group. use table or salt

a. of those surveyed 1122 reported owning a cell phone. use this information to construct a 90% confidence interval estimate of the proportion of all americans age 8-18 who own a cell phone. round answer three devcimal places

b. of those surveyed 1727 reported owning an mp3 player music player. use this information to construct a 90% confidence interval for the proportion of all americans age 8-18 who own an mp3 music player. round answer three decimal places