Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta

Interpolating between statistical table values watch

    • Thread Starter
    Offline

    22
    ReputationRep:
    There are questions such as: January 2012, S1, Q7, (b) where the markscheme uses statistical values of z (from the normal distribution to 4 decimal places) however, the z-value are given to 2 d.p in the tables provided by Edexcel.

    Now, I can easy get to 0.5244 by using some linear interpolation:

    \frac{0.53-0.52}{0.7019 - 0.6985} = \frac{x - 0.52}{0.7-0.6985} to find the value that corresponds to \Phi(z) = 0.7 - but with the number of marks that the markscheme awards for this value, I can't see my way of doing it possibly being the intended way - what is the intended way for S1?
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Zacken)
    There are questions such as: January 2012, S1, Q7, (b) where the markscheme uses statistical values of z (from the normal distribution to 4 decimal places) however, the z-value are given to 2 d.p in the tables provided by Edexcel.

    Now, I can easy get to 0.5244 by using some linear interpolation:

    \frac{0.53-0.52}{0.7019 - 0.6985} = \frac{x - 0.52}{0.7-0.6985} to find the value that corresponds to \Phi(z) = 0.7 - but with the number of marks that the markscheme awards for this value, I can't see my way of doing it possibly being the intended way - what is the intended way for S1?
    See the formula booklet (Page 21 of the PDF, Page 19 of the booklet).

    They have that table for 'nice' values of p so you should have a look there first.

    Note that it's a table for P(Z>z), but hopefully you can see why they chose that value for this question - if not, let me know.
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by SeanFM)
    See the formula booklet (Page 21 of the PDF, Page 19 of the booklet).

    They have that table for 'nice' values of p so you should have a look there first.

    Note that it's a table for P(Z>z), but hopefully you can see why they chose that value for this question - if not, let me know.
    Right, okay, that makes a ton more sense! I've got P(z < 0.7) = P(z > 0.3) so I get my value in that table! I didn't know that table existed, to be honest, thanks for that!
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Zacken)
    Right, okay, that makes a ton more sense! I've got P(z < 0.7) = P(z > 0.3) so I get my value in that table! I didn't know that table existed, to be honest, thanks for that!
    Strictly speaking, you have that P(Z<z) = 0.7 and so P(Z>z) = 0.3 where z = (w-.../...) but I get what you mean, and yes, it is pretty well hidden in the booklet.
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by SeanFM)
    Strictly speaking, you have that P(Z<z) = 0.7 and so P(Z>z) = 0.3 where z = (w-.../...) but I get what you mean, and yes, it is pretty well hidden in the booklet.
    That was a Latex fail on my part. :facepalm: I meant:

    \displaystyle P(Z > z) = 1 - P(Z < z)



    Many thanks! Enjoyed your new blog post by the way, it wouldn't let me rep you though.Nor can I rep you on this.
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Zacken)
    That was a Latex fail on my part. :facepalm: I meant:

    \displaystyle P(Z > z) = 1 - P(Z < z)



    Many thanks! Enjoyed your new blog post by the way, it wouldn't let me rep you though.Nor can I rep you on this.
    Thanks, I am doing revision and keeping track of what I'm learning so I will talk about what I've been learning, I've just been terrible so far on that front, so sorry!

    Good luck with your applications by the way (interview invite soon?
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by SeanFM)
    Thanks, I am doing revision and keeping track of what I'm learning so I will talk about what I've been learning, I've just been terrible so far on that front, so sorry!

    Good luck with your applications by the way (interview invite soon?
    How's the Algebra course going? Still lost or are you planning a massive revision session soon to go over the notes and learn it all properly?

    Hopefully! Interview invites go off starting next week! :eek:
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Zacken)
    How's the Algebra course going? Still lost or are you planning a massive revision session soon to go over the notes and learn it all properly?

    Hopefully! Interview invites go off starting next week! :eek:
    Still lost, just building up momentum by doing other modules

    Good luck! :rave::rave:
    Offline

    3
    ReputationRep:
    (Original post by Zacken)
    How's the Algebra course going? Still lost or are you planning a massive revision session soon to go over the notes and learn it all properly?

    Hopefully! Interview invites go off starting next week! :eek:
    There used to be actual threads for A level, it used to be called the A Level Megathread. Are these still going?


    Posted from TSR Mobile
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by I am Ace)
    There used to be actual threads for A level, it used to be called the A Level Megathread. Are these still going?


    Posted from TSR Mobile
    I've heard of those before, and I'm pretty sure they're still going and they'd be in the Sixth Form -> A-Level subforum.

    Although, there's specifically an A-Level thread for Maths and Further Maths in this forum if that's what you're looking for.
    Offline

    20
    ReputationRep:
    most advanced calculators have normal table functions.
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by the bear)
    most advanced calculators have normal table functions.
    Yeah, I've got a TI-Nspire, cba to use it though.
    Offline

    3
    ReputationRep:
    (Original post by Zacken)
    I've heard of those before, and I'm pretty sure they're still going and they'd be in the Sixth Form -> A-Level subforum.

    Although, there's specifically an A-Level thread for Maths and Further Maths in this forum if that's what you're looking for.
    Yea that's what I mean dude, I'm always on my phone so can never get it. Can you link me it?


    Posted from TSR Mobile
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by I am Ace)
    Yea that's what I mean dude, I'm always on my phone so can never get it. Can you link me it?


    Posted from TSR Mobile
    http://www.thestudentroom.co.uk/show....php?t=3470381
    Offline

    8
    (Original post by SeanFM)
    Still lost, just building up momentum by doing other modules

    Good luck! :rave::rave:
    Are there optional modules for Euclid's Elements?
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Marxist)
    Are optional modules for Euclid's Elements?
    The what now?
    Offline

    8
    (Original post by SeanFM)
    The what now?
    Sorry I was meant to ask if there was an optional module where you use sophisticated ways to derive geometric formulas.
    Offline

    3
    ReputationRep:
    Can't rate on iPad, cheers. Can you post A2 level stuff on it?


    Posted from TSR Mobile
    • Thread Starter
    Offline

    22
    ReputationRep:
    (Original post by I am Ace)
    Can't rate on iPad, cheers. Can you post A2 level stuff on it?


    Posted from TSR Mobile
    Yeah, don't think anybody's gonna mind
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Marxist)
    Sorry I was meant to ask if there was an optional module where you use sophisticated ways to derive geometric formulas.
    I think you can see these pages:

    http://www.bath.ac.uk/catalogues/201...SMA-AFB15.html

    http://www.bath.ac.uk/catalogues/201...SMA-AFM09.html

    I haven't looked too much into the pure options for 3rd year and beyond so I'm not sure, but there may well be.

    If there's anything else we can VM as this thread has served it's purpose.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: November 11, 2015
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.