People were polled on how many books they read the previous year. Initial survey results indicate that s = 1?.8 books. Complete parts {a} through (d) below. a Click the icon to view a partial table oi critical values. {a} How many subjects are needed to estimate the mean number of books read the previous year within six books with 90% condence? This 90% condence level requires 24 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 three books with 90% condence? This 90% condence level requires 96' subjects. (Round up to the nearest subject.) (a) What effect does doubling the required accuracy have on the sample size? A. Doubling the required accuracy neany doubles the sample size. .-.V B. Doubling the required accuracy neany quadruples the sample size. C. Doubling the required accuracy neany quarters the sample size. D. Doubling the required accuracy neany halves the sample size. (it) How many subjects are needed to estimate the mean number of books read the previous year within six books with 99% condence? This 99% condence level requires subjects. (Round up to the nearest subject.)