VCE General & Further Maths Question Thread!

[TheCommando]

Hi, im doing some transformations stuff and am having trouble with getting an answer back out of the equation.

To put it simply, the transformation i did was 1/y vs x and it turned out to (-1.441e-5) + x(2.34e-5)
how do i get an answer out of this? it needs to be somewhere around 6 thousand to make sense in the data.

the original least squares regression line was 1151.58 - 411.8x.

any help is appreciated.

Hey, whatwas the original question?

[BSmith]

i have attached both the data set, the equation  worked out from that through regression and the transformations i have done. 1/price was the strongest but i am unsure how to take the new equation and get the price data from it.

[TheCommando]

Ok so when u fill in that data of the age of corola which should be on the x axis as it is the explanatory response and the prive should be the y as it is the response variable you should see. Non linear line that goes straight that curves to the right, therefore according to the forumlas you need you change your x axis by 1over x or your y axis by 1/yaxis or your x axis by kig x ir tour yaxis by log y.

Im going to change my x acis to 1/x and you will see that it is now linear. Remember to do this you go back to list and spread shits and add a new collum and call it xsq as it cant be x which would be the same name as the x column. and underneath it press = 1/xand select variable refrence and you should see a list of values

Then go back to your graph and change the x axis by clicking on it to 1/x and then press menu-analyze-regression-show linear and thats your equation, plug in 10 to the x in that equation and u have your answer for 5c.
(Yep so my equation was y=15399.3x + 2683.59

[BSmith]

Don't you then have to transform that answer again to get the real answer. Also I am struggling to work out 1/y which is 1/price. As it gives me an answer has such small values. I get how to transform it but when I plug in 10 the answer comes out as 0.147... which isn't right.

[BSmith]

Ok so when u fill in that data of the age of corola which should be on the x axis as it is the explanatory response and the prive should be the y as it is the response variable you should see. Non linear line that goes straight that curves to the right, therefore according to the forumlas you need you change your x axis by 1over x or your y axis by 1/yaxis or your x axis by kig x ir tour yaxis by log y.

Im going to change my x acis to 1/x and you will see that it is now linear. Remember to do this you go back to list and spread shits and add a new collum and call it xsq as it cant be x which would be the same name as the x column. and underneath it press = 1/xand select variable refrence and you should see a list of values

Then go back to your graph and change the x axis by clicking on it to 1/x and then press menu-analyze-regression-show linear and thats your equation, plug in 10 to the x in that equation and u have your answer for 5c.
(Yep so my equation was y=15399.3x + 2683.59

I got that also, I'm looking to work out 1/price. I got an answer but I don't know how to derive a solution from the equation.

[TheCommando]

By transform what do u mean
Also if i did 1/y instead of 1/x i would not get an answer coming out as a big value. I have a small value
This is correct because in your first picture the equation of 1/y vs age is -.0000144x-.0000234x which is the equation i got and when u plug in 10 u shouldnt get a big value
But when i did 1/x it worked and seemed to fit i with the current trend of data. I dont think 1/y works. Correct me if im wrong
I reckon theres something wrong with the question im not sure sorry, as it said right there that the equation of the graph of 1/y vs price was thoose long lists of 0s and decimals points so u cant really get a big answer out of that

[BSmith]

Yeh I thought it was about perculiar. 1/y gave the strongest r value but like you said, given how many .000 are in it, I don't know how to get a decent answer out of it. I'll just use the next strongest. Thanks you for your time.

[AngelWings]

So how do i attach more pages to them

Taping pages in is fine, iirc. I would double check the guidelines on VCAA and with your teacher in case. Pretty sure I did this with my Methods one.

In my opinion though, I would recommend that you just add a small stack of blank printer paper to the end, tear off the cover of your bound reference notebook and get it properly bound at your local Officeworks or favoured binding place for a few dollars. (It's almost always under $10, even with the fancier backings and spines.) If it is one of those books where the pages are hard to tear because they were originally A3 pages (usually your average < $1 exercise book), such as this or these, then cut at the crease where the spine is so you actually have separate A4 pages before binding.

[TheCommando]

Taping pages in is fine, iirc. I would double check the guidelines on VCAA and with your teacher in case. Pretty sure I did this with my Methods one.

In my opinion though, I would recommend that you just add a small stack of blank printer paper to the end, tear off the cover of your bound reference notebook and get it properly bound at your local Officeworks or favoured binding place for a few dollars. (It's almost always under $10, even with the fancier backings and spines.) If it is one of those books where the pages are hard to tear because they were originally A3 pages (usually your average < $1 exercise book), such as this or these, then cut at the crease where the spine is so you actually have separate A4 pages before binding.

How about cutting at the red line?

[drepwns]

Would it be appropriate to use that term in VCE Further math? I know that it's recognised as a term in Excel, but would using the term 'Q4' or 'Fourth quartile' be applicable? Thanks!

[Hungry4Apples]

I assume so, however I (2016 further maths-49) would probably say the top 25% or something to do with the percentages but 'fourth quartlie' should be g. I suggest reading through the exam reports and see how the suggested answers have written it in the past!

[agb99]

hey
i am stuck on the attached questions, any help will be appreciated.....

thanks!

[Hungry4Apples]

hey
i am stuck on the attached questions, any help will be appreciated.....

thanks!

So for question one, three median smothing and five median smoothing are very similar. It works by taking the data point we want to smooth and then using the points around it to find the 'middle value'. So for an example of three median smoothing, take data point 2, we compare data points 1,2 and 3 and take the 'middle' value and replace data point 2 with that value. FIve median moving works the same except we take two to the left and two to the right.
a) i - we have values 30 (point 3), 40 (point 4) and 22.5 (point 5), since 30 is the middle value it is the value of point 4 after 3 median smoothing

For the second question we use the formula Seasonal Index=Actual Figure/Desonalised Figure

so Deseasonalised Figure = Actual Figure/Seasonal Index

DF=AF/1.2 in this case

Since we are dividing by 1.2, we are basically multiplying AF by 1/1.2 or 0.83

1-0.83=.17, so we are reducing the AF by 17%

For the second q

[drepwns]

Hey there,
if I write out the coefficient of determination (r^2) as both a decimal and a percentage, is that okay?
I did so in my SAC today, and I'm feeling very anxious as to whether I lost a mark for that or not.
Thanks!

[drepwns]

Hello again,
so today in my SAC - I used both the correlation coefficient and the residual plot to suggest the superior predictive model.
I recognise that using the coefficient of determination is the right way, but yet again - the pressure under SAC conditions eats away at me.
Is using the correlation coefficient alright, or was I meant to use the coefficient of determination? Thanks.