I've not got any predictions but I know that advantages/disadvantages of a sample/census and comparing distributions will definitely be on the test.
Good luck to everyone taking the test!!
QUICK QUESTION !! You know for the trend line and the seasonal moving averages. You know the question ( usually the last part ) it says estimate the .... for 2008 quarter 2. Use your answer to part (d). How do you know whether to add it or take it away ?! Also another question - when drawing the line of best fit do you draw it through the mean ?
QUICK QUESTION !! You know for the trend line and the seasonal moving averages. You know the question ( usually the last part ) it says estimate the .... for 2008 quarter 2. Use your answer to part (d). How do you know whether to add it or take it away ?! Also another question - when drawing the line of best fit do you draw it through the mean ?
You don't have to take it away at all. I always add my seasonal variation.
You use the value (from part (d)) as
seasonal variation = actual value - trend value estimated mean seasonal variation = mean of all seasonal variation
If this value is negative, you add it to the value from the trend line so your answer should be smaller than the value from the trend line. If this value is positive, you also add it to the value from the trend line.
predicted value = trend line value (as read from trend line on graph) + estimated mean seasonal variation
You can check the answer using the graph. If the actual values for quarter 2, 2007 and quarter 2, 2006 are below the trend line, your estimated value for quarter 2, 2008 should also be below the trend line.
You don't have to take it away at all. I always add my seasonal variation.
You use the value (from part (d)) as
seasonal variation = actual value - trend value estimated mean seasonal variation = mean of all seasonal variation
If this value is negative, you add it to the value from the trend line so your answer should be smaller than the value from the trend line. If this value is positive, you also add it to the value from the trend line.
predicted value = trend line value (as read from trend line on graph) + estimated mean seasonal variation
You can check the answer using the graph. If the actual values for quarter 2, 2007 and quarter 2, 2006 are below the trend line, your estimated value for quarter 2, 2008 should also be below the trend line.
Hope that helps!!
Oh ok thank you so much for this help !! Much appreciated. How are you feeling about tomorrow's exam ?
I think it's likely they are going to ask about; Normal Distribution Time series (including moving averages) Spearman's Rank Histograms Interpreting data Maybe Binomial Distribution!
Yeah, same. How are you revising?? I've done all the past papers so I'm panicking a little... I don't want to do the older ones like June 2010 because they're a little irrelevant.
Yeah, same. How are you revising?? I've done all the past papers so I'm panicking a little... I don't want to do the older ones like June 2010 because they're a little irrelevant.
Same here, I've reviewed all the past papers, reviewed all the topics and now i'm like what do i do. Yeh i agree How are you revising ?