This doesn't seem to make sense. The question states "Carry out a test based on the linear regression model to determine whether the underlying rate of increase in AIDS cases exceeds 500 per quarter" but the unit of the x-values is in years not quarters. (see page 7) I'm not convinced that beta should be set to 0.5 in the null hypothesis, if a quarterly rate of increase of 500 is being tested then surely beta should be 2 (i.e. an increase of 2000 per year which is the same as 500 per quarter). Otherwise, I would have thought that the x -values should be set to 4 x the year then everything is being treated as quarters, not a mixture of years and quarters. If anyone could shed some light on why beta = 0.5 in the null hypothesis I'd be very grateful. Thanks
Error in notes? Thanks for pointing this out. The confusion arises because the quarters are in successive years. Whereas in our linear regression I guess we are ignoring this (and I suppose assuming they are successive quarters). Hmm, I think I will reword the example (or just change it) to prevent this confusion in the notes next year. Again, thanks for pointing this out. John
No problem Just relieved that I'm not going mad and misunderstanding the questions! While you're at it you might want to amend page 9 of chapter 14, question 14.7 There's a bar missing on the Y.. in the formula for the treatment effect estimate PS. Am I correct in thinking the CT3 notes I'm using (I purchased them prior to the September 06 exams) are exactly the same as the notes for the April sitting when I plan to take it? I didn't register with the institute in time for the September sitting. Are the CT notes only updated annually, and if so, is it the April or September sitting when the new set of notes are first used? Thanks
The notes are refreshed every calendar year in line with changes to core reading, and thus exams. So April notes are valid for September in the same year, but after that you will need updates/new ones Either available here http://www.acted.co.uk/Html/paper_cmp_upgrade.htm or you can order them from acted for £10 i think. There's not too many changes for CT3 this year, but worth getting.
Thanks for this Stevie. I have corrected the notes and will have the updated corrections document (with replacement pages) available shortly on: http://www.acted.co.uk/Html/paper_corrections.htm Yup "Actuary" is correct. They are updated annually and released in September ready for the following April and September exams. The major changes are listed in our upgrade document which can be downloaded free of charge from our website (thanks Actuary for the link) or ordered in the usual way for a nominal charge.
