ATAR Notes: Forum
VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: hifer on November 05, 2007, 01:03:35 pm
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My Answers :D
1. A
2. B
3. A
4. D
5. C
6. C
7. C
8. D
9. D
10. E
11. E
12. C
13. E
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got the same :D :D
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Here are my answers (i think i made like 2 mistakes :cry: )
Core-
1.A
2.B
3.A
4.D
5.C
6.C
7.C
8.D
9.A (Misread qn ahhh!)
10.B(Probably wrong :()
11.E
12.C
13.E
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9 is D i put them in my calc twice using L1 as x and L3 as logy then do LinReg
10 is 2 categorical variables, which according to my book is segmented bar charts
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I got 4 wrong which is a fabulous result for me!!!!
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I got the same except for:
12. B
10. D
Someone explain where I went wrong on 12?
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I got the same except for:
12. B
10. D
Someone explain where I went wrong on 12?
Well here's how i did it ...
Entered each point into the calculator, and used the med-med function (sure it's time consuming but you get a more accurate answer)
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I got the same except for:
12. B
10. D
Someone explain where I went wrong on 12?
12. did u divide it into 3 parts at each 12 month interval, then get the median of the 2 outer parts, draw a line between them
then i took rise/run
rise/run = (6000-4000)/(24-12)
= 166.6667
LOL or do what odette said :shock:
Q10. it cant be D,C,A cos they all involve numerical variables, we are only dealing with 2 categorical variables
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100% oooh yeah.
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12) is C
cha ching
but i screwed up Q9) i know what i did wrong
i got 2 wrong in the core, cause im an idiot and didnt read the question properly
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I hated that qn 12! idiotic makin ya find the three med on a plot like that... i got 6.5 and 30.5 for the median x-values and 3000 and 7000 for y, getting C
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10 is 2 categorical variables, which according to my book is segmented bar charts
where in the book is that? i said a
can someone give a brief explanation of each of those 5 types?
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Essential maths page 109
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for Question 10, the answer should be A.. a scatter plot
As for the other solutions does not work
Histogram: univariate
back-to-back stem-leaf plot: compares categorical and numerical
parallel box plot: same thing as stem plot
"A" segmented percentage bar chart: segmented bar charts are univariate so with a single bar chart you cannot compare two variables
as each categorical notions are defined with a number, they can both be seen as 2 numerical data, hence allowing a scatter plot to be used
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for Question 10, the answer should be A.. a scatter plot
As for the other solutions does not work
Histogram: univariate
back-to-back stem-leaf plot: compares categorical and numerical
parallel box plot: same thing as stem plot
"A" segmented percentage bar chart: segmented bar charts are univariate so with a single bar chart you cannot compare two variables
as each categorical notions are defined with a number, they can both be seen as 2 numerical data, hence allowing a scatter plot to be used
thats what i thought *cough* i just looked at scatter plot and went yeah that would work and the others wouldnt, clearly i didnt think it through properly but yeah, thanks man
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a scatter plot would not work
you would assume that there would be atleast one case of each
as such you would get a plot that looks like the channel 9 old logo with nothing to actually show, just 9 points. dont know what percentage of high salary earners have what.
it's segmented bar charts.
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a scatter plot would not work
you would assume that there would be atleast one case of each
as such you would get a plot that looks like the channel 9 old logo with nothing to actually show, just 9 points. dont know what percentage of high salary earners have what.
it's segmented bar charts.
Agreed. I think they are just trying to confuse us by giving them numbers.
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but as nh4n said, you would need multiple bar charts, is that right?
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you would need multiple bars within the one bar chart yes.
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ok got you
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but the fact is that, you cannot compare the two variables even if u had two segmented bar chart within the one. u cannot see if someone that has a high salary level, will have a small/medium or large car. all you are doing with 2 segmented bar charts is showing their percentages respectively, and independently, the question clearly ask for how to link the relationship between the two.. you cannot relate the two with segmented bar charts
but with a scatter plot u can, as the point (1,2) would indicate someone with a small car with a medium salary level
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but the fact is that, you cannot compare the two variables even if u had two segmented bar chart within the one. u cannot see if someone that has a high salary level, will have a small/medium or large car. all you are doing with 2 segmented bar charts is showing their percentages respectively, and independently, the question clearly ask for how to link the relationship between the two.. you cannot relate the two with segmented bar charts
but with a scatter plot u can, as the point (1,2) would indicate someone with a small car with a medium salary level
|3|
|2|
|1| <--- salary
|1|
|1|
1---------2--------3 (car size)
does that graph makes sense? i only drew one bar, should be 3
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alright now tell me, what percentage of ppl with a small car have a high salary? cos your graph is only displaying one side, you're only telling us how much percentage of low/high/medium salary level have a small/medium/car respectively. you cannot from the graph see what percentage of ppl with a small car have a low/medium/high salary
answers can be found at http://www.itute.com/mathline/2007_vcaa_fm_exam1_sol.pdf
it says for 10: A
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alright now tell me, what percentage of ppl with a small car have a high salary? cos your graph is only displaying one side, you're only telling us how much percentage of low/high/medium salary level have a small/medium/car respectively. you cannot from the graph see what percentage of ppl with a small car have a low/medium/high salary
answers can be found at http://www.itute.com/mathline/2007_vcaa_fm_exam1_sol.pdf
it says for 10: A
I totally agree lol :)
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how can you tell any percentages with a scatter plot. it ONLY tells us that yes, someone with a small salary has a small car. doesnt tell us anymore.
check this graph i just made
(http://i197.photobucket.com/albums/aa237/eddy144/barhcar.jpg)
there you go.
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alright ahashake, now tell me.. from your graph. what is the percentage of ppl with a low income that has a large car?, like other guy u only showing one side as well cause your only showing what percentage of low/medium/high salary earning have a small/medium/large car respectively
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[img]http://aycu11.webshots.com/image/30970/2005929908196050465_th.jpg[/img]
heres a scatter plot that i drew
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haha that shows absolutely nothing.
only that yes, someone with income level 1 has a car of size level 2. mine shows that PLUS the percentage breakdown of what type of cars are owned by each level of salary.
what do you think yours shows?
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aha u still cant see that ur graph only shows one side? only showing what percentage of ppl with a small/medium/large car have a low/medium/high income, it cannot show the reverse like u cannot see from the graph what percentage of ppl with a low income have a large car, cant u see that fact?
i know the scatterplot is not perfect for displaying these 2 variables, as they are catagorial "made into" numerical. however it is the best one out of the 5 to used
once again answers are at http://www.itute.com/mathline/2007_vcaa_fm_exam1_sol.pdf
10:A
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No. By your logic segmented bar charts are useless because they only show 'one side'. When have you ever seen a scatter plot like your one? It shows absolutely nothing and shows no relationship other than an unspecified amount of X salary earners have a car size of Y. Mine shows the breakdown.
A scatter plot is made to show relationships and how one variable affects another. Your scatter plot does not show this in the slightest.
Just because iTute says it doesnt meant it is right. Give it a few days and there will be a 'Thanks to John Smith for correctly pointing out that for Core, Question 10 is E'.
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WHAT THE HELL? a scatter plot does not have to show how one variable affects the other, we want it to.. thats why we make transformations. like is name, a "scatter" plot can be just a bunch of random points with no correlation what so ever. plus from my graph u can also see the breakdown, just count the amount of the repeated dots divided by the total number of dots, multiply by a 100, there u get ur %.
PLUS a segmented bar chart is not useless, it is used for "univariate" a method of showing information of 1 variable
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Oh ok.
So that is why segmented bar charts are in the chapter 'Displaying and describing relationships between two variables'?
Of course! Because in my crazy maths book two means one!
How are you meant to count repeated dots? . how many does are in that full stop? I counted 15. How many do you count?
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you can have a key, or like in the exams, have the list of points above graph. theres no point arguing with u, u just cant see that ur graph only shows one side. just study for tomorrow's exam and we will wait what the assessment report has to say
also in hienemen book segmented bar charts are under univariate
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You cant see that your scatter plot shows absolutely nothing.
What did you get /40, out of interest?
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i see both of ur points
segmented bar chat only show the effect of iv on dv
whilst scatter plot graph only have 3x3 points, its impossible to interpret information from it, cos u'll have dots overlap.
the question asked it is "best displayed using "which graph?
i reckon segmented bar chat is a little better
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nothing wrong with overlapping points.
and if 10 is A, i would get 40/40 right
yourself?
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wtf
10 cant be A
the text book clearly states that two categorical values = a segmented bar chart
this is crap
that means i can kiss a 30 goodbye
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hey guys,
been keeping up with your posts lol :P
the answer to question 10 should be E because
A- scatterplot
B- histogram
C- parallel boxplots
D- back- to- back stemplot
are used to display numerical data.
however, segmented bar charts can be constructed from a two-way frequency table- which is for categorical data. chapter four in further maths essential has an example on page 90 showing a segmented bar chart constructed from this two-way frequency table.
in relation to the question where the two variables are 'size of car' and 'salary level' car size is dependant on salary level and the segmented bar chart should depict the horizontal axis with salary level low, medium and high and the vertical axis should have the percentages of those with a car size small, medium or large.
hope that helps :)
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There we go *insert witty name here* just backed everything me and others had been saying.
To nh4n, I got 40/40. Looks like you got 39 hey? Oh.
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wow, someones grumpy.
learn to deal with exam stress imo
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There we go *insert witty name here* just backed everything me and others had been saying.
To nh4n, I got 40/40. Looks like you got 39 hey? Oh.
hey 39 is still great, plus we dont know who is right until the assessment reports come out. plus im happy with what a got for no studying all year, i have specialist to attend to. the question is very vague and no one can be absolutely sure, so we have to wait and see :)
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haha grumpy?
yeh thats me. stress head. really stressed...
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itute had changed their solution regarding to that question
after consideration, the answer is E, like i said the question asked it is "best displayed using "which graph? and it appeared segmented bar chart is a bit better
NOTE: For Core Q10, the writer has chosen A because the writer believed that a regression line can be obtained if it exists and a r-value can then be determined. However in a scatterplot, points having the same numbers cannot be separated and appeared to be just one point, hence some information is lost. The requirement of the question is to best display (not determine) the relationship, thus it appears that E is the best answer
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booyah.
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There we go *insert witty name here* just backed everything me and others had been saying.
To nh4n, I got 40/40. Looks like you got 39 hey? Oh.
hey 39 is still great, plus we dont know who is right until the assessment reports come out. plus im happy with what a got for no studying all year, i have specialist to attend to. the question is very vague and no one can be absolutely sure, so we have to wait and see :)
haha, that's hilarious. spesh child ^5
how'd you find the spesh exam...pretty straight forward wasn't? Although, EXAM 2 determines our marks booya :(
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"The categorical data are converted to numerical. A" - itute
Does that change anything?
Soz if already been posted
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"The categorical data are converted to numerical. A" - itute
Does that change anything?
Soz if already been posted
OMG THEY'VE BEEN ARGUING ABOUT THAT ALL DAY.... DONT REMIND THEM LOL!!
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There we go *insert witty name here* just backed everything me and others had been saying.
To nh4n, I got 40/40. Looks like you got 39 hey? Oh.
My, do I have to slap you on the wrist for that? That was pretty spiteful, please watch yourself the next time you feel the urge to be mean!
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lol AhaShake,
didn't take a couple of days
took a couple of hours more like :)
sick sick now i can go into exam two with a smile on face, gonna be a drainer writing all the answers into my bound reference T_T
gl people
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today is big day guys, good luck ya'll
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GOOD LUCK ALL,
hope their isn't a question on deseaonslise, i've done nothing on it
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GOOD LUCK ALL,
hope their isn't a question on deseaonslise, i've done nothing on it
Hate to disappoint you but it will definitely be on there i think ... good luck
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but i have been doing 2005 and 2006 paper it wasnt there
i hope it will be on normal thats most easy