Week 5 Project Assignment. Use MS Work

For EACH of the 2 majors, consider the ‘School Type’ column.  Construct a 90% confidence interval for the proportion of the schools that are ‘Private’.  

Answer these questions in MS Word.  (This is the interpretation part, and the information here belongs in your paper)

a.  In Week 1, you found the percentage of schools that were private for business from our sample of schools on the spreadsheet. What percentage was that?

b.  In Week 1, you found the percentage of schools that were private for engineering from our sample of schools on the spreadsheet. What percentage was that?

c.  If we knew the exact percentage of schools that were private in Week 1, why did we do a confidence interval to give us a range of the percentage of schools that are private?  How is what it is showing us different than what we did in Week 1?  Why is this interval potentially MORE useful to the student deciding between majors?

d.  For our person who is deciding which major gives the better ROI, compare the RANGE of each confidence interval. Which one is more helpful, and why?

e.  Why would public vs. private matter to a potential college student?

For EACH of the 2 majors, construct a 99% confidence interval for the mean of the column ‘Annual % ROI’.

Answer these questions in MS Word.  These ideas go in your Week 8 paper.

a.  In Week 2, you learned to find the mean in Excel.  What is the mean annual percent ROI for our sample business majors on the spreadsheet?

b. For the sample in our spreadsheet, what is the mean annual percent ROI for engineering majors? 

c.  If we knew the exact mean in Week 2, why did we do a confidence interval?  How is it showing us something a bit different? Why is this interval actually MORE useful to the student deciding between majors?

d. Is a 99% confidence interval a GUARANTEE that the ROI will be in the interval? Why or why not?   (This is how your Week 8 paper will end, so make sure this is clear.)

e.  Compare the business interval and the engineering interval.  Which seems better?  Why?