VCE General & Further Maths Question Thread!

[keltingmeith]

Would the first (blue) one be negatively skewed, how so would it be positively skewed?

Because the median drifts to the positive side of the IQR.

[Cosec]

Because the median drifts to the positive side of the IQR.

If the median is on the right-er hand side from the middle within the IQR, wouldnt it then be negatively skewed?

[RazzMeTazz]

Currently in class we are doing the Geometry and Trigonometry module.
I didnt quite understand how to do this textbook (Maths Quest) question (based on the sine rule)

The answers :

a.)129.1 degrees
b.) 68km

Thanks!

[Escobar]

Question:
The number of goals scored by the gal attack each week for a netball team would be best represented in a:
a) histogram
b) frequency diagram
c) frequency polygon
d) pie chart
3) cumulative frequency graph

What is the difference between options a), b) and c)?
(a) is correct

[keltingmeith]

Question:
The number of goals scored by the gal attack each week for a netball team would be best represented in a:
a) histogram
b) frequency diagram
c) frequency polygon
d) pie chart
3) cumulative frequency graph

What is the difference between options a), b) and c)?
(a) is correct

a) implies continuous data
b) implies discrete data
c) is used to give a shape to the data.

a) is correct because, since we're working in time, we have continuous data, so we use a histogram. (before someone jumps in with "but we're using discrete time!!", it's still considered as continuous data) You should be familiar with the difference between discrete and continuous data, and what graphs imply which. If you're not, say you're not, because I know that most textbooks do a pretty poor job of teaching it.

Currently in class we are doing the Geometry and Trigonometry module.
I didnt quite understand how to do this textbook (Maths Quest) question (based on the sine rule)

The answers :

a.)129.1 degrees
b.) 68km

Thanks!

Sorry RazzMeTazz, I missed you!! >.<;
I'm going to have to draw this one out, but I don't have time right now, sorry. :\ If no one gets back to you before tomorrow afternoon, I'll have something for you.

[Escobar]

thanks; I understand 

[Mintyfreshmints]

I have a transition matrix diagram question:
In a transition matrix diagram do you have to label a loop around a point, with 100%, if there is no transition away from that point? E.g A proportion of 1 of the people at A will be at A after the next transition...
If you do not label the 100% loop on the diagram is it still technically correct or not? Because to me it seems redundant however I can also see why it should be there.

[RazzMeTazz]

Thanks EulerFan101!



Also, can anyone please explain the difference between a vertex and an apex? Thanks!

[TheAspiringDoc]

Thanks EulerFan101!



Also, can anyone please explain the difference between a vertex and an apex? Thanks!

to quote MathIsFun (very useful btw):

Apex=The point (vertex) furthest from the base of an object.

[keltingmeith]

Thanks EulerFan101!



Also, can anyone please explain the difference between a vertex and an apex? Thanks!

I am so sorry RazzMeTazz - I wrote up a post earlier, but for whatever reason it's gone!! Thankfully, I kept the image, see attached. (edit: Apparently it's too large, grrrr. Explains why it didn't post last time, though... If you still want it, PM me an e-mail, I'll send it that way. Otherwise, see statement

Basically, I disagree with the way it's worded - it makes no sense, and following it their answers seem to make no sense (note: I did initially read it wrong and went straight north instead of west, but it basically means my triangle is rotated 90 degrees clockwise from what it should be - all values would be exactly the same)

I have a transition matrix diagram question:
In a transition matrix diagram do you have to label a loop around a point, with 100%, if there is no transition away from that point? E.g A proportion of 1 of the people at A will be at A after the next transition...
If you do not label the 100% loop on the diagram is it still technically correct or not? Because to me it seems redundant however I can also see why it should be there.

Yes, you should. If A doesn't point to itself, and doesn't point to anything else, then the interpretation is that we can't continue on from A. However, this makes no sense, since the idea of a transition matrix is that it can be applied an infinite amount of times. So, A should always continue on to something, even if this means you must point it to itself.

Alternatively, if you have no loop, someone else reading your information would just assume you've forgotten about it, and would have no idea where A actually goes, and might just make a guess which completely ruins your data.

(note: I don't know how strict VCAA are on this - I'm speaking strictly from a statistician's point of view)

[TheAspiringDoc]

Um, how do you solve this?
If a+2 = 7, find the value of 3a-12 without solving for a.
I can solve it easy, I just don't get the 'without solving for a' part..
Thanks! 

[LoadedWithPotatoes]

a+2 = 7, multiply 3 by both sides
3a+6= 21, subtract 18 from both sides

Therefore, 3a-12=3

[Escobar]

how many decimal points do we round answers to if it is not specified?

[kinslayer]

how many decimal points do we round answers to if it is not specified?

In a VCAA exam, if you are required to give an answer in decimal form, you will always be told how many decimal places to round to. In such a case, always try to carry as many significant digits as your calculator gives you and only round the final answer.

[Sardothienn]

In a further core sac are we suppose to draw residuals/ scatterplots and all those other charts accurately? It just seems too time consuming tbh