Instructions: Answer each question, and when required explain your answer. Your explanation must be clear and complete. You may refer to your book, your notes and your homework papers.
 Problems 15 and 16 on p. 712.
 Suppose ACT scores in a particular year are approximately normally distributed with mean 20 and standard deviation of 6.
 (a) What z value does 29 represent?
 (b) Use the table on page 709 to determine the proportion of testtakers
that receive a 29 or better on the ACT test.
 (c) What ACT score must you get if 69.15% of testtakers
received a higher score?
 An American Research Group poll of a nationwide random sample of 2,104 likely voters was conducted by telephone March 25, 2007. It showed Clinton 42% and McCain 45% (with 10% Undecided). Determine a 95% confidence interval for the 45% McCain figure. Show how you compute your answer.

 A factory produces widgets. The manager believes that only 2% of the widgets produced are defective. How large a sample should the manager take to be 95% sure that the actual rate of defective widgets is between 1% and 3%?
 Problem 27 on p. 741.