Likely to appear tricky questions

[Lear]

Wow I just realised quite a few of my prediction did come up. Especially financial, Graphs and Stats

[vceme]

Wow I just realised quite a few of my prediction did come up. Especially financial, Graphs and Stats

haha the whole time i was doing the exam, i'm like woahhh this is just like the forum predictions
any more accurate predictions for exam 2....? 

[Lear]

I’ll make a list later in the day

[studyingg]

Sometimes they allude to concepts that would be on exam 2, in exam 1. So, I guess it's good to look through exam 1, and think of possible short-answer questions that could be on exam 2.

[vceme]

-integer solutions
-maybe draw up boxplots with outliers. the whiskers end at the maximum. minimum value that aren't considered outlier
-probably interpretations of box plots
-a question about effective interest rate/ which one is better to use?
-there was a lack of identifying constraints so might have to write up a constraint from information
-seasonal correction was absent on exam 1

i feel like core analysis will be more challenging than usual....

[fatimah.el]

What does effective interest rate measure, and how do you know when to use it, as in what would the question usually ask?
With this year exam (exam 1), question 19 core was asking for which loan costs the least amount of money at the end of the year, and they used effective interest rate. But Why?

[Lear]

What does effective interest rate measure, and how do you know when to use it, as in what would the question usually ask?
With this year exam (exam 1), question 19 core was asking for which loan costs the least amount of money at the end of the year, and they used effective interest rate. But Why?

Hello and welcome to the forums.
As we know when interest rate compounds the interest incurred varies depending on the value each time period.
Using effective interest rate we can find the >simple interest equivalent< for a year.

For example let’s say I took out a loan of 5000 dollars with 3% p.a compounding monthly.
Using financial solver we can find that the value of my loan in 12 months will be 5152.08

Now if we did eff(3,12) on the cas we can find the effective interest rate which is 3.01416%

You’ll notice when we add 3.01416% to the 5000 loan for the whole year using the simple interest method (1+ (3.01416/100))*5000 it will give us 5152.08.

This is same as what we got using compound interest. This can be very useful for comparing loans and investments (as was required the question on exam 1) because you don’t have to try out every single option on financial solver and figure out how much interest was incurred. Instead, you can simple find the effective interest rate and compare this easily across loans.
Have a shot at the exam 1 question now and let us know if you need more help.

[Lear]

Tricky things that may appear on Exam 2

Statistics
-   Emphasis on drawing histograms/boxplots. Perhaps with a log10 x axis
-   Required to draw a graph with outliers that are NOT clear and must be recognised
-   Deseasonalise data with 2-3 years and x number of seasons in each. Find seasonal indices.
-   Questions with purposely deceptive scales on x and y axis
-   Use a scatterplot to describe an association that may actually be non-linear and not linear as commonly asked
-   Given a residual plot explain why the association is likely to be non-linear
-   Median smoothing with numbers higher than 5, not just typical 2-4 and 3-5
-   Sig figs = decimal points
-   Switched up x and y axis in question.
-        Interpretation of Z score, use of Z score to compare values, convert from Z score to score.


Financial
-   Required to write a rule rather than recurrence. There’s a difference.
-   Unit cost depreciation with a few things going on
-   Lump sum calculation for investment/loan to reach x in certain number of years
-   Interest earned from a compounding investment where payments were also made.
-   Trick questions where % interest is given per month or week NOT per annum. Do not assume.
-   Understanding of how perpetuities and annuities work.



Matrices
-   Create a matrix that, when multiplied by a matrix of interest, shows only specific rows/columns not all of them
-   Create a permutation matrix that would transform a column matrix with a certain word to another matrix that shows this word rearranged.
-   Emphasis on understanding of dominance matrices, one step and two step matrices. For example, given two step matrix and some information, find one step matrix.
-   Understanding of how transition matrices work (what rows are multiplied by what columns) and being able to show calculations
-   Find percentage/number of objects of interest changed using transition matrices when given a condition. For example – Consider objects who had >trait< in 2015, how many of these also had >trait< in 2014
-   Able to manipulate transitions in the form TSn + B to go backwards. For example given 2015 matrix, find 2010 matrix.
-   Put in words what the B matrix represents.

Graphs and relations
-   Being able to find integer solutions on a given line when object function has same gradient as an inequality (see 2017 NHT VCAA Exam 2)
-   Being able to find solutions when objective function has a gradient very close to another inequality.
-   Being able to recognise that if all number on a line are a solution, the gradient of the objective function must be the exact same as this line. See 3d 2016 VCAA
-   Being able to find the distance between two lines. 2012 VCAA Exam 2 Question 2D

[Seno72]

Tricky things that may appear on Exam 2

Statistics
-   Emphasis on drawing histograms/boxplots. Perhaps with a log10 x axis
-   Required to draw a graph with outliers that are NOT clear and must be recognised
-   Deseasonalise data with 2-3 years and x number of seasons in each. Find seasonal indices.
-   Questions with purposely deceptive scales on x and y axis
-   Use a scatterplot to describe an association that may actually be non-linear and not linear as commonly asked
-   Given a residual plot explain why the association is likely to be non-linear
-   Median smoothing with numbers higher than 5, not just typical 2-4 and 3-5
-   Sig figs = decimal points
-   Switched up x and y axis in question.
-        Interpretation of Z score, use of Z score to compare values, convert from Z score to score.


Financial
-   Required to write a rule rather than recurrence. There’s a difference.
-   Unit cost depreciation with a few things going on
-   Lump sum calculation for investment/loan to reach x in certain number of years
-   Interest earned from a compounding investment where payments were also made.
-   Trick questions where % interest is given per month or week NOT per annum. Do not assume.
-   Understanding of how perpetuities and annuities work.



Matrices
-   Create a matrix that, when multiplied by a matrix of interest, shows only specific rows/columns not all of them
-   Create a permutation matrix that would transform a column matrix with a certain word to another matrix that shows this word rearranged.
-   Emphasis on understanding of dominance matrices, one step and two step matrices. For example, given two step matrix and some information, find one step matrix.
-   Understanding of how transition matrices work (what rows are multiplied by what columns) and being able to show calculations
-   Find percentage/number of objects of interest changed using transition matrices when given a condition. For example – Consider objects who had >trait< in 2015, how many of these also had >trait< in 2014
-   Able to manipulate transitions in the form TSn + B to go backwards. For example given 2015 matrix, find 2010 matrix.
-   Put in words what the B matrix represents.

Graphs and relations
-   Being able to find integer solutions on a given line when object function has same gradient as an inequality (see 2017 NHT VCAA Exam 2)
-   Being able to find solutions when objective function has a gradient very close to another inequality.
-   Being able to recognise that if all number on a line are a solution, the gradient of the objective function must be the exact same as this line. See 3d 2016 VCAA
-   Being able to find the distance between two lines. 2012 VCAA Exam 2 Question 2D

Also correcting for seasonality might come up although thats more like an exam 1 question

[Poet]

For those doing the networks module:

- The use of Euler's formula.
- the ability to correctly follow the Hungarian algorithm
- The use of cuts through a graph, and finding the correct one
- Trick questions including dummy paths on weighted graphs
- Dijkstra's algorithm (this was alluded to in examination 1)
- Float times, crashing and/or critical path analysis.

Good luck everyone!

[VeryJuicyLemon]

Geometry
-Asking to find the cost of a product in proportion to a particular scale (volume, area...)
-Surface area questions which may exclude an area that isn't specified (e.g. swimming pool, top is excluded)
-Always look out for ambiguous case of sine when using the sine rule
-Find the difference of time for 2 particular cities but sometimes you need to include "next day, day before",
-Finding the smaller circle radius


-Sun rise from east to west

[vceme]

-   Create a permutation matrix that would transform a column matrix with a certain word to another matrix that shows this word rearranged.

any tips for this?

There could also be a residual plot graph, and students are asked to complete it  just like the typical median smoothing graphs

[Lear]

any tips for this?

Nope, you just have to learn to do it from the textbook (that's what I did). I'll put a practice question up for this in a bit if I get the time.

EDIT : Here's a practice question on this for further folk. Feel free to private message me a picture of your solution to check if it is right (Although you'll probably be able to tell whether it is right or not simply from your CAS)

Matrix Q = [P O S T]
Q  x   S = [S T O P]

Find the 4x4 matrix S

[Omarrr_2163]

If you were to

Tricky things that may appear on Exam 2

Statistics
-   Emphasis on drawing histograms/boxplots. Perhaps with a log10 x axis

With the log 10 x axis would you just have a normal histogram (plug it on cas) and then apply a log10 x transformation to it and then construct it on paper?

[Lear]

Ideally they will just give ranges on which you have to draw the histogram. For example they may give data ranging between 0 and 1,000,000 and give x axis ranges on the axis between 0-1, 1-2, 2-3, 3-4, 4-5, 5-6.

You’ll just need to convert the values give into log form and decide where to place them on the histogram.