In a survey on supernatural experiences, 722 of 4001 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 4001 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 4001 people formed a random sample of adult Americans. We need to assume that there are only 722 adult Americans. We need to assume that the 722 people are the only Americans who had seen or been with a ghost. We need to assume that the 4001 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. We are 90% confident that the proportion of all adult Americans who have seen or been with a ghost is within this interval. 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 confident that 90% of the proportion of all adult Americans who have seen or been with a ghost is within this interval. 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)? narrower wider