In a survey on supernatural experiences, 722 of 4019 adult Americans surveyed reported that they had seen or been with a ghost. (a) What assumption must be made in order for it to be appropriate to...

Extracted text: In a survey on supernatural experiences, 722 of 4019 adult Americans surveyed reported that they had seen or been with a ghost. (a) What assumption must be made in order for it to be appropriate to use the formula of this section to construct a confidence interval to estimate the proportion of all adult Americans who have seen or been with a ghost? O we need to assume that the 722 people are the only Americans who had seen or been with a ghost. O we need to assume that the 4019 people formed a random sample of adult Americans. O Wwe need to assume that there are only 722 adult Americans. O we need to assume that the 4019 people were surveyed at a supernatural convention. (b) Construct a 90% confidence interval for the proportion of all adult Americans who have seen or been with a ghost. (Round your answers to three decimal places.) Interpret the interval. O We are confident that the proportion of all adult Americans who have seen or been with a ghost is within this interval 90% of the time. We are 90% confident that the proportion of all adult Americans who have seen or been with a ghost is within this interval. O we are confident that 90% of the proportion of all adult Americans who have seen or been with a ghost is within this interval. O we are 90% confident that the proportion who have seen or been with a ghost is within this interval. (c) Would a 99% confidence interval be narrower or wider than the interval computed in part (b)? O narrower O wider