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****Leaving Certificate: Higher Level Maths Discussion****

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    #1082
    Peregrine
    Moderators, Education Moderators Posts: 26,402 Mod ✭✭✭✭Peregrine


    If it makes you feel any better, I made the exact same mistake. I stared at it for a few seconds wondering why the slope was negative, quickly corrected it and tried to pretend nothing happened :o


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    #1083
    plmko
    Registered Users Posts: 160 ✭✭plmko


    Where did ye say that the worked out results can be found?


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    #1084
    robman60
    Registered Users Posts: 2,224 ✭✭✭robman60


    plmko wrote: »
    Where did ye say that the worked out results can be found?

    http://www.studentxpress.ie/HLProjectMaths/index.html


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    #1085
    plmko
    Registered Users Posts: 160 ✭✭plmko


    plmko wrote: »
    Where did ye say that the worked out results can be found?
    robman60 wrote: »
    http://www.studentxpress.ie/HLProjectMaths/index.html

    Thankyou very much!


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    #1086
    Aspiring
    Registered Users Posts: 2,204 ✭✭✭Aspiring


    Q7 up now, paper 2 going well so far :D


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    #1087
    FatRat
    Registered Users Posts: 3,194 ✭✭✭FatRat


    Aspiring wrote: »
    Q7 up now, paper 2 going well so far :D

    Looks spot on alright. Thought I got 45 in that but apparently for the interquartile range you round to the higher number? I averaged the 2nd and 3rd number and averaged the 7th and 8th and got the interquartile from that... Isnt that more accurate or is it wrong?


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    #1088
    Moody_mona
    Registered Users Posts: 1,107 ✭✭✭Moody_mona


    Always round up for quartiles.


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    #1089
    lostatsea
    Registered Users Posts: 320 ✭✭lostatsea


    FatRat wrote: »
    Looks spot on alright. Thought I got 45 in that but apparently for the interquartile range you round to the higher number? I averaged the 2nd and 3rd number and averaged the 7th and 8th and got the interquartile from that... Isnt that more accurate or is it wrong?

    Finding the quartiles for a data set of 10 items can be tricky. The lower quartile place value is 0.25(n + 1), where n is the number of items in the data set. However, I don't think it was meant to be done this way for Project Maths. All they want you to do is just divide the data set into 2 sets of five. The quartiles are the middle value in each data set of five.

    However, your way is more strictly correct.


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    #1090
    FatRat
    Registered Users Posts: 3,194 ✭✭✭FatRat


    lostatsea wrote: »
    Finding the quartiles for a data set of 10 items can be tricky. The lower quartile place value is 0.25(n + 1), where n is the number of items in the data set. However, I don't think it was meant to be done this way for Project Maths. All they want you to do is just divide the data set into 2 sets of five. The quartiles are the middle value in each data set of five.

    However, your way is more strictly correct.

    That's what I figure. They should mark it correct. In fact I'd say its more correct. In a set of ten, 3-8 isn't the the two middle quarters. Makes no sense but anyway we'll leave it at that.


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    #1091
    lostatsea
    Registered Users Posts: 320 ✭✭lostatsea


    FatRat wrote: »
    That's what I figure. They should mark it correct. In fact I'd say its more correct. In a set of ten, 3-8 isn't the the two middle quarters. Makes no sense but anyway we'll leave it at that.

    These are the correct values for this question:
    Lower quartile: 1 798 750

    Median: 1 847 800

    Upper quartile: 1 978 575

    My belief, as stated earlier, is that this technique is not required for the leaving cert.


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    #1092
    Carcar123
    Registered Users Posts: 3 ✭Carcar123


    MegGustaa wrote: »
    No the bell curve has to do with the allocation of marks, ie how they weight specific questions within a 25-marker. In order to game the bell curve, they "frontload" marks into easier sections. Everyone gets the easier ones, few get the hardest ones completely correct. So you get a lot of passes, fewer A1s. All this goes on at the marking conference after the Leaving Cert, where each subject and paper's marking scheme is finalised before the markers go off with their bag of scripts. That's my understanding of how the process works.

    Once the marking scheme has been finalised every paper has to be marked according to that, regardless of the standard of the other papers it happened to be in with. Especially in a subject like Maths where there are clear-cut answers. They don't fiddle with the marks so that every examiner has X amount of As, Bs etc. because they'd be caught out by students viewing and appealing their marks, surely.

    I know we've all heard of examiners being told to go back and remark their papers because there's too many As but that's more likely to be in the more subjective subjects like English and Irish, or where it was determined that the examiner applied the marking scheme too loosely.

    Actually they do fiddle with marks. If there's too many or too little a's they change the marking scheme to suit it, it's the same in every subject!


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    #1093
    plmko
    Registered Users Posts: 160 ✭✭plmko


    Moody_mona wrote: »
    Always round up for quartiles.

    I thought it was round up if it's a decimal and get the average of it and the one above if it's a whole number no? (Regardless of what you're looking for)


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    #1094
    Aidanmull
    Registered Users Posts: 1 ✭Aidanmull


    Hey =)
    i just made an account because i'm wondering is something going to be done about this... i dunno if this is right category

    Anyway, In The english version of paper 1 we were asked to find 'a' in question 6 part B, in the irish version of the paper however they were asked to find 'x' for the same question..
    Did anyone else notice this? has anything been said about this?


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    #1095
    Irish_gal
    Registered Users Posts: 9 ✭Irish_gal


    looking at those solutions I definitely failed!! :'(


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    #1096
    robman60
    Registered Users Posts: 2,224 ✭✭✭robman60


    I thought I did well in paper 2 but things aren't looking quite as positive now. Does anyone feel they misinterpreted the last part of both the statistics and probability long questions?


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    #1097
    LC767
    Registered Users Posts: 10 ✭LC767


    Would you be punished had you said the null hypothesis was that the drug is more successful? That screwed up the second part of the question :/


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    #1098
    Yulkmn
    Registered Users Posts: 99 ✭✭Yulkmn


    PAPER 2
    Q2 the proof part which is (a)
    could you do that another way? I filled cos2a to be something else that was in the log tables and sin2a to be something else in the log tables and in the end it equaled that cos2a.
    so is that okey??


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    #1099
    T0001
    Registered Users Posts: 695 ✭✭✭T0001


    Yulkmn wrote: »
    PAPER 2
    Q2 the proof part which is (a)
    could you do that another way? I filled cos2a to be something else that was in the log tables and sin2a to be something else in the log tables and in the end it equaled that cos2a.
    so is that okey??

    Thats what I did, and our teacher said it would be ok.


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    #1100
    kevin12345
    Registered Users Posts: 1,171 ✭✭✭kevin12345


    Irish_gal wrote: »
    looking at those solutions I definitely failed!! :'(

    Don't stress yourself out about not having the same solutions as everyone on boards. I freaked myself out last year when the majority of my answers were different to those on here and I still came out with a C1 in HL. It's all about the methods you used and attempting questions that gets you the marks.

    Try to enjoy your summer and don't be fretting about failing anything just yet. :)


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    #1101
    Isitthough?
    Registered Users Posts: 192 ✭✭Isitthough?


    kevin12345 wrote: »
    Don't stress yourself out about not having the same solutions as everyone on boards. I freaked myself out last year when the majority of my answers were different to those on here and I still came out with a C1 in HL. It's all about the methods you used and attempting questions that gets you the marks.

    Try to enjoy your summer and don't be fretting about failing anything just yet. :)
    That post actually gave me hope :D Ty was worried too after seeing the solutions


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    #1102
    FatRat
    Registered Users Posts: 3,194 ✭✭✭FatRat


    All of the solutions are on that student express website now. I did better than I expected in paper 2.


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    #1103
    plmko
    Registered Users Posts: 160 ✭✭plmko


    looking at those sample answers just make me sad...thought I did better...


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    #1104
    romanita
    Registered Users Posts: 35 ✭romanita


    LC767 wrote: »
    Would you be punished had you said the null hypothesis was that the drug is more successful? That screwed up the second part of the question :/

    I said the same thing :/


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    #1105
    chatterboxxx95
    Registered Users Posts: 306 ✭✭chatterboxxx95


    romanita wrote: »
    I said the same thing :/

    Me too. Honestly, I don't see how they can penalise for having the hypothesis the wrong way round, our teacher always said it didn't matter which was null and which was alternative, as long as you do the maths in between and accept the right one!
    Obviously though marks can be lost for the 2nd part that it screwed up but I'd say they'll have to go easyish on the marking of that part because there is an obvious discrepancy there! I realised they wanted it the other way around after i did the hypothesis test so wrote them a note in part two to explain i didn't have time to change the above :cool:


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    #1106
    lostatsea
    Registered Users Posts: 320 ✭✭lostatsea


    chatterboxxx95 wrote: »
    Me too. Honestly, I don't see how they can penalise for having the hypothesis the wrong way round, our teacher always said it didn't matter which was null and which was alternative, as long as you do the maths in between and accept the right one!
    Obviously though marks can be lost for the 2nd part that it screwed up but I'd say they'll have to go easyish on the marking of that part because there is an obvious discrepancy there! I realised they wanted it the other way around after i did the hypothesis test so wrote them a note in part two to explain i didn't have time to change the above :cool:

    Your teacher was wrong. It matters at the most fundamental level.

    Let us say my company develops a new drug. If it is not better than the existing drug I keep my head down and say nothing.

    If, after testing, we find it is better, we make that claim. The null hypothesis accepts the status quo (i.e. the present drug is better and the new drug is less effective). This is the null hypothesis.

    The hypothesis test is based on this assumption. If the test (based on the 95% significance test) shows this not to be true, then you reject the null hypothesis and accept the claims of the company that their drug is more successful.

    This is basic, straight forward statistical analysis which teachers should be drumming into their students.


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    #1107
    romanita
    Registered Users Posts: 35 ✭romanita


    lostatsea wrote: »
    Your teacher was wrong. It matters at the most fundamental level.

    Let us say my company develops a new drug. If it is not better than the existing drug I keep my head down and say nothing.

    If, after testing, we find it is better, we make that claim. The null hypothesis accepts the status quo (i.e. the present drug is better and the new drug is less effective). This is the null hypothesis.

    The hypothesis test is based on this assumption. If the test (based on the 95% significance test) shows this not to be true, then you reject the null hypothesis and accept the claims of the company that their drug is more successful.

    This is basic, straight forward statistical analysis which teachers should be drumming into their students.

    My teacher was absolutely crap, I can honestly say she would have really struggled with that paper. She always avoided explaining hard questions to us because she couldn't do them herself :/


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    #1108
    MegGustaa
    Registered Users Posts: 232 ✭✭MegGustaa


    lostatsea wrote: »
    Your teacher was wrong. It matters at the most fundamental level.

    Let us say my company develops a new drug. If it is not better than the existing drug I keep my head down and say nothing.

    If, after testing, we find it is better, we make that claim. The null hypothesis accepts the status quo (i.e. the present drug is better and the new drug is less effective). This is the null hypothesis.

    The hypothesis test is based on this assumption. If the test (based on the 95% significance test) shows this not to be true, then you reject the null hypothesis and accept the claims of the company that their drug is more successful.

    This is basic, straight forward statistical analysis which teachers should be drumming into their students.

    Where students would have been confused, I think, is that the types of question for hypothesis testing we normally do (at least in my class, I obviously can't speak for others) involve a company/group making a claim that, for example, 75% of people like their product. A group is sampled to see how many of them like the product. You decide if that is enough evidence to support the group's claim that 75% like the product, right?

    In that case, we were taught to take the null hypothesis as that what the company is saying is correct. Assume their claims are true until proven otherwise. So in the exam I had a hard time deciding what the null hypothesis was because we'd never covered an example of a company claiming one thing was better than another.

    It's my teacher's fault for over-simplifying the rule for determining what a null hypothesis is, but I'm still annoyed about it. The status quo thing is quite straight-forward and makes total sense to me now. I was questioning it in the exam but I didn't have time to do it out again with the reverse H0.

    I did all the Maths out properly for the first part of that, so I'm hoping I only lose a few marks for stating the null hypothesis and my conclusion incorrectly. Also hoping they frontload the marks for that question and the last part isn't worth much...


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    #1109
    FatRat
    Registered Users Posts: 3,194 ✭✭✭FatRat


    I questioned the null hypothesis a few days ago, I'd say it was 50/50 between those who wrote the alternative instead of the null. I'm happy I got it right but the same thing was on the test last year and in the marking scheme it literally says to deduct one mark if you didn't write the hypothesis correctly. All of the marks are going for the calculations.


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    #1110
    romanita
    Registered Users Posts: 35 ✭romanita


    FatRat wrote: »
    All of the marks are going for the calculations.

    That's a relief


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    #1111
    MegGustaa
    Registered Users Posts: 232 ✭✭MegGustaa


    FatRat wrote: »
    I questioned the null hypothesis a few days ago, I'd say it was 50/50 between those who wrote the alternative instead of the null. I'm happy I got it right but the same thing was on the test last year and in the marking scheme it literally says to deduct one mark if you didn't write the hypothesis correctly. All of the marks are going for the calculations.

    I wonder how that will impact on the last part, then.

    I hope they give at least some marks for a logical answer that follows from the incorrect null hypothesis given. I said it was 500/500 because I was assuming Drug B was more successful and theoretically that was the maximum number of people. So obviously I didn't do any calculations...

    Realistically that part should have been a clear indication that I had the null hypothesis backwards. It made me question it in the exam alright, I wish I had just gone with my instinct and done it out again. I guess all I can do now is hope many people did the same thing and they don't take off much for it!


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