題組內容

II. The significance level is 0.05 for all questions in II unless otherwise specified.

1. (10%) A market research firm estimates the proportion of adults in a city who have tablets, and they believe more than half of the adults in this city have tablets. A confidence interval for the population proportion of adults have tablets from a random sample of 400 adults is constructed. The lower limit is 0.5597 and the upper limit is 0.6403.



(1) \( (5\%) \) Determine the level of confidence used to construct the confidence interval.