Having trouble? Send me your questions. I will post questions of general interest and my answers.

 Q: We were wondering where the Real Estate information was for problem 2-52?

A: It is in Appendix I on pages 519-520. But it is also on the CD so that you need not enter all those numbers. Once you've installed the CD (instructions are printed on the CD), go to Data, then to Appendix and get the file RealEstate.xls.

Chapter 6: Continuity correction:

 Q: I am not really confident in using the continuity factor yet, could you please explain when it is used? 

A: The most important thing to remember is that you will use the continuity correction factor ONLY when you are approximating a binomial probability with the normal distribution. (As you mentioned, this approximation is only appropriate when np>5 and nq>5.) If X is already a continuous, normally distributed random variable, no correction is required.

Q: How do I decide whether to add 0.5 or subtract 0.5? 

A: If you draw a picture, then the direction of the correction should be obvious. It is possible to write a specific formula for each case. Let a and b represent particular values of a Binomial random variable, X. 

08/24/06 
Eastwood asked:  "Some students have complained of difficulties in downloading an Excel spreadsheet I have posted for them, saying that they were prompted for a username and password. Other students seem to have encountered no difficulties. One student suggested a  "work around" solution: he was able to paste the data into another spreadsheet."