People were polled on how many books they read the previous year. Initial survey results indicate that sequals =17.4 books. Complete parts ?(a) through ?(d) below.
?(a) How many subjects are needed to estimate the mean number of books read the previous year within four four books with 90?% ?confidence?
This 90% confidence level requires 52 subjects. ?(Round up to the nearest? subject.)
?(b) How many subjects are needed to estimate the mean number of books read the previous year within two books with 90?% ?confidence?
This 90% confidence level requires nothing subjects. ?(Round up to the nearest? subject.)