4. (16 points] A 500-page book contains 250 sheets of paper. The thickness of the paper used to manufacture the book has mean 0.08 mm and standard deviation 0.01 mm. a. [8 points) What is the probability that a randomly chosen book is more than 20.2 mm thick (not including the covers)? b. [8 points) What is the 10th percentile of book thicknesses? (See Homework 2 for definition of pth percentile).