Results 1 to 5 of 5

Math Help - Basic correlation question

  1. #1
    Senior Member
    Joined
    Apr 2009
    Posts
    308

    Basic correlation question

    I'm tossing up between a. and e. and I don't have the answers, what do you guys think is the correct choice?

    Thanks

    This is the question:

    http://img4.imageshack.us/f/asdfyn.jpg/
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    I can't read the text in the image

    CB
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor Unknown008's Avatar
    Joined
    May 2010
    From
    Mauritius
    Posts
    1,260


    A scientist has found that there is a correlation of r = -0.39 between eye colour (black, green, brown) of guinea pigs and the amount of alcohol that is fatal to the animal when consumed. This indicates:
    a. nicotine is less harmful to one eye colour than the others.
    b. one must always consider the eye colour of animals in making statements about the effect of nicotine consumption.
    c. the researcher needs to do further study to explain the causes of this negative correlation.
    d. the researcher needs to take a course in statistics because correlation is not an appropriate measure of categorical variables.
    e. the lethal dose of nicotine goes down as the eye colour of the animal changes.
    Here it is.

    But I'm surprised that the question is implying that alcohol contains nicotine... ethanol is present in alcohol and nicotine is found in tobacco.

    But I would say d. I haven't studied linear regression, but I don't think that colours can be put on an axis and a certain relationship put. I would have accepted if they put the wavelength or frequency of the colour, but not discrete colours.
    Last edited by Unknown008; September 16th 2010 at 02:16 AM. Reason: Didn't notice that the image would still be small... follow the link image to see the original
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by usagi_killer View Post
    I'm tossing up between a. and e. and I don't have the answers, what do you guys think is the correct choice?

    Thanks

    This is the question:

    Imageshack - asdfyn.jpg
    1. the correlation is small

    2. As there is no inherent ordering of eye colour the correlation is meaningless (choose three random number ~U(0,1) sort them into descending order and compute the correlation, also consider the distribution of the correlation between the three numbers unsorted)

    3.The text metions alchol the answers nicotine, maybe typos?

    4. d, seems OK but for incomplete reasons

    CB
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by CaptainBlack View Post
    1. the correlation is small

    2. As there is no inherent ordering of eye colour the correlation is meaningless (choose three random number ~U(0,1) sort them into descending order and compute the correlation, also consider the distribution of the correlation between the three numbers unsorted)
    The SD of r^2 for three random numbers sampled from U(0,1) is ~=0.7, so even if this were a valid process it would be of no significance.

    CB
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. correlation question
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: September 5th 2011, 02:05 AM
  2. Correlation Question
    Posted in the Statistics Forum
    Replies: 1
    Last Post: May 12th 2010, 08:07 AM
  3. Correlation Coefficient Question
    Posted in the Statistics Forum
    Replies: 1
    Last Post: May 11th 2010, 02:03 PM
  4. True/false question on correlation?
    Posted in the Statistics Forum
    Replies: 0
    Last Post: December 3rd 2009, 05:09 PM
  5. Correlation Coefficient Question
    Posted in the Business Math Forum
    Replies: 1
    Last Post: August 12th 2009, 10:58 AM

Search Tags


/mathhelpforum @mathhelpforum