People were polled on how many books they read the previous year. Initial survey results indicate that s= 13.5 books. Complete parts (a) through (d) below. Click the icon to view a partial table of...

Extracted text: People were polled on how many books they read the previous year. Initial survey results indicate that s= 13.5 books. Complete parts (a) through (d) below. Click the icon to view a partial table of critical values. (a) How many subjects are needed to estimate the mean number of books read the previous year within six books with 90% confidence? This 90% confidence level requires subjects. (Round up to the nearest subject.) Partial Critical Value Table Level of Confidence, Critical Value, Za/ 2 (1- a) • 100% Area in Each Tail, 2 90% 0.05 1.645 95% 0.025 1.96 99% 0.005 2.575