1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Anyone know Statistics?

Discussion in 'Off-Topic Discussion' started by memario1214, Feb 16, 2011.

  1. Feb 16, 2011 at 7:05 PM
    #1
    memario1214

    memario1214 [OP] Hotshot Offroad Moderator Vendor

    Joined:
    Oct 1, 2009
    Member:
    #23628
    Messages:
    19,815
    Gender:
    Male
    First Name:
    Colton
    Missoula, MT
    Vehicle:
    SOLD - 05 Dub Cab TRD Sport 4x4, CURRENT - '21 Tundra MGM Limited
    I am having a beast of a time with confidence intervals right now and am completely zoning out on it, for I haven't seen it for quite some time. Anyone able to help me out?
     
  2. Feb 16, 2011 at 7:07 PM
    #2
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    I took a few classes of stat but I don't remember the equations or anything.
     
  3. Feb 16, 2011 at 7:11 PM
    #3
    memario1214

    memario1214 [OP] Hotshot Offroad Moderator Vendor

    Joined:
    Oct 1, 2009
    Member:
    #23628
    Messages:
    19,815
    Gender:
    Male
    First Name:
    Colton
    Missoula, MT
    Vehicle:
    SOLD - 05 Dub Cab TRD Sport 4x4, CURRENT - '21 Tundra MGM Limited
    Well, here's one of the questions...

    A random sample of 160 commercial customers of PayMor Lumber revealed that 32 had paid their accounts within a month of billing. The 90% confidence interval for the true proportion of customers who pay within a month would be...?
     
  4. Feb 16, 2011 at 7:15 PM
    #4
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    Yeah there's going to be an equation that uses the number of people sampled (n) to caclulate a range such that if you conducted the same survey 100 times, the number of people who said yes would fall in the "confidence interval" range 90 of those times.
     
  5. Feb 16, 2011 at 7:18 PM
    #5
    Gieser

    Gieser Official Flatlander

    Joined:
    Jun 17, 2010
    Member:
    #39110
    Messages:
    856
    Gender:
    Male
    MB, Canada
    Vehicle:
    06 tundra yamaha edition
    scion Head Unit and magnaflow muffler...so far
    i remember leaning this but i cant remember...and that was only last year:frusty:
     
  6. Feb 16, 2011 at 7:22 PM
    #6
    crf69

    crf69 scraping my emblems off my plasti-dip

    Joined:
    May 18, 2010
    Member:
    #37348
    Messages:
    3,578
    Gender:
    Male
    First Name:
    Ryan
    Ohio
    Vehicle:
    06 TRD OR BSP cab'n 1/2
    ummm yeah
    statistics?
    90% wrong 60% of the time or something like that
     
  7. Feb 16, 2011 at 7:26 PM
    #7
    06ToyTaco

    06ToyTaco Well-Known Member

    Joined:
    Dec 7, 2008
    Member:
    #11369
    Messages:
    194
    Gender:
    Male
    CA
    Vehicle:
    06 4x4 DCLB Sr5 Silver
    OME 885X, 1.5" AAL + TSB, LR UCA

    Using those numbers in the appropriate type of test and the bell curve, you can come to the conclusion that over such interval you have significance evidence that "32/160 customers pay within a month" happens 90% of the time.

    The 90% is the area under the curve. In this case, it is a 2-sided p-value of .05 (5%).
     
  8. Feb 16, 2011 at 7:27 PM
    #8
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    Oh man it's all coming back to me now.

    You basically repeated what I said earlier, but you did it in a way that was actually concise and intelligent sounding. :laugh:
     
  9. Feb 16, 2011 at 7:28 PM
    #9
    memario1214

    memario1214 [OP] Hotshot Offroad Moderator Vendor

    Joined:
    Oct 1, 2009
    Member:
    #23628
    Messages:
    19,815
    Gender:
    Male
    First Name:
    Colton
    Missoula, MT
    Vehicle:
    SOLD - 05 Dub Cab TRD Sport 4x4, CURRENT - '21 Tundra MGM Limited
    The bell is starting to jingle, but it's not ringing yet.
    My answers are:
    a. .148-.252
    b. .138-.262
    c. .144-.256
    d. .153-.247
    e. None of the above
     
  10. Feb 16, 2011 at 7:30 PM
    #10
    PatHLC128

    PatHLC128 College.

    Joined:
    Aug 29, 2008
    Member:
    #8867
    Messages:
    1,260
    Gender:
    Male
    First Name:
    Pat
    Austin, TX
    Vehicle:
    09 TRD Off Road 4x4 AC
    OME complete 3" kit, 265/75/16 Cooper STTs, Pro Comp 7089 wheels, Shrockworks sliders, UWS Low Pro Toolbox, AFE Pro-Dry S, OEM Bedmat, Ventvisors, Husky Liners, Tint, De-badged
    I just started a 'Prob & Statistics for Engineering and the Sciences' course and it's harder for me than multivariable calculus was...I hate it.
     
  11. Feb 16, 2011 at 7:31 PM
    #11
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    Huh? I was expecting something like "28-36" or something like that.

    Or are those percentages..... 32/160=0.2 That's got to be it.
     
  12. Feb 16, 2011 at 7:41 PM
    #12
    memario1214

    memario1214 [OP] Hotshot Offroad Moderator Vendor

    Joined:
    Oct 1, 2009
    Member:
    #23628
    Messages:
    19,815
    Gender:
    Male
    First Name:
    Colton
    Missoula, MT
    Vehicle:
    SOLD - 05 Dub Cab TRD Sport 4x4, CURRENT - '21 Tundra MGM Limited
    I figured it out!!!!!!! But I have like 10 to do and it's due at 9. I will post back here after then
     
  13. Feb 16, 2011 at 7:44 PM
    #13
    06ToyTaco

    06ToyTaco Well-Known Member

    Joined:
    Dec 7, 2008
    Member:
    #11369
    Messages:
    194
    Gender:
    Male
    CA
    Vehicle:
    06 4x4 DCLB Sr5 Silver
    OME 885X, 1.5" AAL + TSB, LR UCA
    Null Hypothesis is that proportion (32/160) pay each month, while the Alternative Hypothesis is that any other proportion except 32/160 pay each month.

    Since the chance of that happening each month is so small you have a tighter/smaller interval. Therefore the intervals are so small

    I am getting
    (0.149383-0.259167) for 1 proportion test.
    (0.147985, 0.252015) for normal approximation 1-proportion test.

    Depending on which one is right (its been a while) i think that its A.

    *note* use at own risk. I do not take accountability if I am wrong :eek:.
     
  14. Feb 16, 2011 at 7:46 PM
    #14
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    I hope that what you picked Colton! :rofl:
     
  15. Feb 16, 2011 at 7:46 PM
    #15
    06ToyTaco

    06ToyTaco Well-Known Member

    Joined:
    Dec 7, 2008
    Member:
    #11369
    Messages:
    194
    Gender:
    Male
    CA
    Vehicle:
    06 4x4 DCLB Sr5 Silver
    OME 885X, 1.5" AAL + TSB, LR UCA
    basically :D. It's been a while since I took the course so i'm right there with you; but with the help of minitab, its easy as pie :eek:
     
  16. Feb 16, 2011 at 7:47 PM
    #16
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    Oh god...minitab! Stop it you are going to give me nightmares :laugh:
     
  17. Feb 16, 2011 at 8:04 PM
    #17
    memario1214

    memario1214 [OP] Hotshot Offroad Moderator Vendor

    Joined:
    Oct 1, 2009
    Member:
    #23628
    Messages:
    19,815
    Gender:
    Male
    First Name:
    Colton
    Missoula, MT
    Vehicle:
    SOLD - 05 Dub Cab TRD Sport 4x4, CURRENT - '21 Tundra MGM Limited
    That actually is NOT the one I picked... For it was wrong lol. Typing up answer now
     
  18. Feb 16, 2011 at 8:06 PM
    #18
    TexasTacoma37

    TexasTacoma37 Well-Known Member

    Joined:
    Sep 3, 2009
    Member:
    #22227
    Messages:
    31,174
    Gender:
    Male
    :popcorn:
     
  19. Feb 16, 2011 at 8:08 PM
    #19
    06ToyTaco

    06ToyTaco Well-Known Member

    Joined:
    Dec 7, 2008
    Member:
    #11369
    Messages:
    194
    Gender:
    Male
    CA
    Vehicle:
    06 4x4 DCLB Sr5 Silver
    OME 885X, 1.5" AAL + TSB, LR UCA
    :popcorn:
     
  20. Feb 16, 2011 at 8:11 PM
    #20
    memario1214

    memario1214 [OP] Hotshot Offroad Moderator Vendor

    Joined:
    Oct 1, 2009
    Member:
    #23628
    Messages:
    19,815
    Gender:
    Male
    First Name:
    Colton
    Missoula, MT
    Vehicle:
    SOLD - 05 Dub Cab TRD Sport 4x4, CURRENT - '21 Tundra MGM Limited
    My equation p±z√(p(1-p)/n) where
    p=32/160=.2
    z for 90% confidence=1.645
    n=160

    .2±1.645√(.2(1-.2)/160)

    therefore 0.148 to 0.252

    I got a shit ton of other ones wrong though so it really doesn't matter...FML
     

Products Discussed in

To Top