in the past, 16% of all homes with a stay-at-home parent, the father is the stay-at-home parent. an independent research firm has been charged with conducting a sample survey to obtain more current information. (a) what sample size is needed if the research firm's goal is to estimate the current proportion of homes with a stay-at-home parent in which the father is the stay-at-home parent with a margin of error of 0.03? use a 95% confidence level.