Sheets of book paper have mean thickness of .01 in and standard deviation .0001 in . A particular book will have 200 sheets of this paper in it. (Ignore the cover for this problem.) Let xi correspond to thickness of the ith page for any one copy of the book.
(a) Which function correctly models thickness of a book copy: 200x or x1 + x2 + ··· + x200? Why?
(b) Find the average book thickness.
(c) Find the standard deviation of book thickness.
(d) Within how many inches from the average book thickness should one expect about 95 % of the book copies to be?