VCE General & Further Maths Question Thread!

[galaxy21]

Hi,
Just wondering whether we need to know about capital gains tax for the current study design? It came up in one of the questions for the 2012 Heffernan exam 2, so thought I should clarify.
If yes, can someone please explain how to work this out?
Thanks!

[Lear]

The only way VCAA can ask a question about that is if they explain what it is in the question and it can be solved using basic further maths techniques.

[galaxy21]

The only way VCAA can ask a question about that is if they explain what it is in the question and it can be solved using basic further maths techniques.

awesome, thanks!

[PopcornTime]

Is there a way to calculate standard deviation using 68-95-99.7% rule apart from case for this data?

Answer is 10.

[Lear]

Considering most of the data (certainly at least 99.7% of it) lies between 30 and 90, you can probably assume that there needs to be 6 standard deviations between 10 and 90. This stems from our knowledge that 99.7% of the data lies between -3sd and +3sd.
So we do 90-30=60
and then 60/6 = 10
Hope it helps

ETA: I guess the above does work on an assumption but similar can be done when considering 68% of the data. Very conveniently 67.5% of the data lies between 50 and 70 so there must be 2 standard deviations in between. (70-50)/2 = 10.  Tbh this is an excellent question that really tests understanding.

[PopcornTime]

How would you compare percentages for this data (that relates to dolphin activity)?

[PopcornTime]

Just need some help with this question.

[studyingg]

How would you compare percentages for this data (that relates to dolphin activity)?

First you need to determine what the explanatory and response variables are, because dolphin activity was the variable being measured in this observational study, (and time is usually explanatory as it does not depend on any other variable), 'activity' is the response variable. Therefore in order to make a comparison between the variables, we will need to compare two different times of day, on the basis of one type of activity.

I think you're confused on how to add up the percentages, and for this one you would need to add up the columns (as this is where the explanatory variables are) conveniently, the sum of each column already adds up to 100, so you will not have to do a calculation.

My answer for this question would be:
The two-way table, suggests that there is an association between the time of day, and observed dolphin activity. For example, the percentage of dolphins who spent time travelling, differed based on whether it was morning, or noon, increasing from 8% to 40%


im pretty sure this is how to answer it... (according to past VCAA questions that are simillar)

[studyingg]

Just need some help with this question.

Answer is E
A: Is definitely false, as the interest paid will vary depending on the present value ( reducing balance loans do not have a fixed interest amount)
B:Not true, because although she missed the payment, interest will still be added to the loan. (think of how this would look like on a graph)
C: This is not true, because not only did she miss a payment, but interest will be added on the loan.
(for questions B and C, u can confirm on the TVM if you are not quite sure)
D:Not true, because she missed the third payment, interest was added to the loan, meaning she would have to pay that off, in adition to her initial plan of repaying the loan with 6*800 (4800) payments
E:True, for the reason I stated in D ^

[marauder52]

I was hoping someone could help me out with 2016 VCAA Exam 2 Graphs and Relations module Question 3D.
Even by looking at the examiners report below I do not understand.


How can they assume that since the gradient = -1 , m=n
There is a link there that I am not understanding.

[MB_]

I was hoping someone could help me out with 2016 VCAA Exam 2 Graphs and Relations module Question 3D.
Even by looking at the examiners report below I do not understand.
(Image removed from quote.)

How can they assume that since the gradient = -1 , m=n
There is a link there that I am not understanding.

If you rearrange \(Q=mx+ny\) in terms of \(y\) you get, \(y=\frac{-m}{n}x+\frac{Q}{n}\). \(\frac{-m}{n}\) corresponds to the gradient of the profit equation so \(\frac{-m}{n}=-1\) therefore \(m=n\)
Hopefully this helps!

[PopcornTime]

Any tips for calculating interest questions?

Having trouble with Q5. c) ii)

[studyingg]

Any tips for calculating interest questions?

Having trouble with Q5. c) ii)

Interest is equal to:

total amount paid - the amount paid off the loan
which is equal to
number of payments*monthly payment amount - initial value of the loan - amount that needs to be paid off (FV)
which for a reducing balance loan that has this relation : V0=x , Vn+1= (1+r/n*100)*Vn -- D
it would be
(D*n) - (V0-Vn)
and for a loan that has been fully paid off it would be
D*n - V0

In your case, the terms of the loan change, which must be accounted for while calculating interest.
 it would equal to:
11000*total number of payments - 480,000

lol I would give you the answer, but idk where my CAS is at the moment 

[PhoenixxFire]

Any tips for calculating interest questions?

Having trouble with Q5. c) ii)

So to do that you'd first work out how much they payed over the first 3 years.
So it would be $11 000 X 12 (3 years X 4 quarters)
So $132 000

Then you'd work out how much they payed after the interest rate change
So using your answer from 5ci. of 73 quarters you would then do 73 X 11000
So $803 000

So in total they payed $132 000 + $803 000
=$935 000

So they borrowed $480 000 and payed $935 000
So interest = $935 000 - $480 000
Interest = $455 000

Edit: Beaten to it, but I do have my CAS so this has the actual values.

[PopcornTime]

Interest is equal to:

total amount paid - the amount paid off the loan
which is equal to
number of payments*monthly payment amount - initial value of the loan - amount that needs to be paid off (FV)
which for a reducing balance loan that has this relation : V0=x , Vn+1= (1+r/n*100)*Vn -- D
it would be
(D*n) - (V0-Vn)
and for a loan that has been fully paid off it would be
D*n - V0

In your case, the terms of the loan change, which must be accounted for while calculating interest.
 it would equal to:
11000*total number of payments - 480,000

lol I would give you the answer, but idk where my CAS is at the moment

I'm just confused with why interest equals total amount of payments - Pv.