Results 1 to 5 of 5

Math Help - standard deviation

  1. #1
    Junior Member
    Joined
    Jun 2007
    Posts
    52

    standard deviation

    I did these questions but im not sure if they are 100% correct since the back of the book is not showing the same answers (my teacher said the book could be wrong alot of the time).

    3. Calculate the standard deviation for the following:

    (17,18, 19, 20, 21, 22, 23, 24, 25, 26)

    5. Find the quartile values, the interquartile range, and the standard deviation of the salaries listed below.

    Salary Frequency
    28000 4
    30000 6
    32000 7
    34000 4
    36000 2
    38000 1
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    Great. What did you get when you did them?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Skoz View Post
    I did these questions but im not sure if they are 100% correct since the back of the book is not showing the same answers (my teacher said the book could be wrong alot of the time).

    3. Calculate the standard deviation for the following:

    (17,18, 19, 20, 21, 22, 23, 24, 25, 26)

    Mr F says: 3.028. (It's possible your book might give 2.872)

    5. Find the quartile values, the interquartile range, and the standard deviation of the salaries listed below.

    Salary Frequency
    28000 4
    30000 6
    32000 7
    34000 4
    36000 2
    38000 1

    Mr F says:Q1 = 30000, Q2 = 32000, Q3 = 34000, IQR = Q3 - Q1, sd = 2722.69 (it's possible your book might give 2665.36)
    Doesn't your teacher have correct answers that s/he can give you?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Jun 2007
    Posts
    52
    No he doesn't give it... ;/
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Dec 2008
    Posts
    1
    I'm pretty sure there are 2 standard deviation equations. Maybe the book and you used different equations. This site gives the 2 equations I'm thinking of:

    Standard Deviation Calculation
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Standard Deviation
    Posted in the Statistics Forum
    Replies: 4
    Last Post: September 8th 2010, 04:05 AM
  2. Replies: 5
    Last Post: May 18th 2009, 05:14 AM
  3. standard deviation and mean deviation
    Posted in the Statistics Forum
    Replies: 1
    Last Post: March 16th 2008, 06:09 AM
  4. i need standard deviation help
    Posted in the Statistics Forum
    Replies: 2
    Last Post: February 22nd 2008, 06:03 PM
  5. The mean and standard deviation
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: February 17th 2008, 09:15 PM

Search Tags


/mathhelpforum @mathhelpforum