Results 1 to 3 of 3

Math Help - using raw scores for standard deviation

  1. #1
    Newbie
    Joined
    Dec 2012
    From
    Sheffield
    Posts
    1

    using raw scores for standard deviation

    Hi,

    I am rubbish at maths, so I apologise for if this question is very simple...

    I am trying to calculate whether a child is eligible for exam dispensation. To be eligible, it states that they must have 'an average, standardised score of 84 or less'.

    I have tested speed of writing. A study of 2701 people found that the average writing speed for a child of his age is 17.8 words per minute (wpm). He wrote at a speed of 11.3wpm.

    If I assume that there will be a normal distribution of the scores, is there a way of working out whether or not the child meets the criteria for exam dispensation (i.e. his standardised score is less than 84?)

    Thanks
    Frantastic
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Sep 2012
    From
    Australia
    Posts
    3,612
    Thanks
    591

    Re: using raw scores for standard deviation

    Hey frantastic.

    When you say 84 is that a percentile? (In other words, is the score in the lower 84% of scores for the normal distribution)?

    If this is the case calculate the test statistic z = (11.3 - 17.8)/sd and find using either tables or a computer P(Z < z).

    We can definitely say that it will be in the bottom 50% since 11.3 < 17.8 so it will definitely be in the bottom 84%.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member estatistics's Avatar
    Joined
    Dec 2012
    From
    worldwide
    Posts
    29

    Re: using raw scores for standard deviation

    Α Statistician can help you with statistics: spss, amos, minitab, R. Regression, factorial analysis, correlation, anova, mediation, moderation.Paypal payment. email:info@estatistics.eu, estatistics
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Standard Deviation
    Posted in the Statistics Forum
    Replies: 5
    Last Post: July 12th 2010, 07:13 PM
  2. Z-Scores and Standard Deviation Help
    Posted in the Advanced Statistics Forum
    Replies: 5
    Last Post: December 15th 2009, 04:27 AM
  3. Replies: 5
    Last Post: May 18th 2009, 04:14 AM
  4. standard deviation and mean deviation
    Posted in the Statistics Forum
    Replies: 1
    Last Post: March 16th 2008, 05:09 AM
  5. Standard Deviation
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: March 11th 2008, 04:20 AM

Search Tags


/mathhelpforum @mathhelpforum